MailerQ blog

We are excited to announce the release of version 1.1 of the AMQPDelayer application. This program is designed to work alongside MailerQ, reducing the load on both RabbitMQ and MailerQ by temporarily removing delayed messages from RabbitMQ and storing them elsewhere. This optional tool helps optimize system performance by alleviating strain on these key components.

We have released version 5.15.0 of MailerQ. In this release, we have introduced new options to control the flow of delayed and temporary messages, as well as fixed multiple bugs. Please note that MailerQ is now more strict in distinguishing between options for exchanges, routing keys, and queues. Therefore, please make sure to gradually deploy this update to ensure your setup is still working as expected. Please check the release notes for more details.

We have released version 5.14.5 of MailerQ. In this release, we have fixed multiple bugs.

We have released version 5.14.4 of MailerQ. In this release, we have fixed multiple bugs.

We have released version 5.14.3 of MailerQ. In this release, we have fixed multiple bugs.

We have released version 5.14.2 of MailerQ. In this release, we have added support for OpenSSL 3.0 to ensure that MailerQ works out of the box on Ubuntu 22.04 and resolved a few minor issues.

We have released version 5.14.1 of MailerQ. In this release, we have resolved a number of minor issues.

We have brought out version 5.14.0 of MailerQ. In this release we have solved a number of small issues, and we have added support for de PROXY protocol for external MTA's.

Begin 2022 we started with a short cycle CI/CD pipeline with YEAR.WEEK based versioning. This was not a success. We have therefore stopped this versioning scheme and have switched back to semantic versioning.

We have installed a new GPG key for our packages.mailerq.com software repository. You need to update your Debian and Ubuntu servers to download future MailerQ software updates.

The past few months we have implemented a new way of releasing and we have fixed some bugs. In this product update, we would like to inform you about the changes in our software.

As of this moment we are changing the way we release MailerQ. We move away from our old release procedure, in which we deployed significant updates with major changes only a few times a year, and replace this with a CI/CD pipeline with way more updates, small changes and bugfixes at shorter intervals.

RabbitMQ version 3.8.15 introduced a standard consumer-timeout which is too low to be used with MailerQ. Therefore we recommend disabling this timeout. This article will show how this is done.

The recent release of MailerQ version 5.13 brings along core performance optimizations and low-level stability improvements. This article provides an overview of key changes

Last year, we wrote an article about the advantages of publishing delivery results to RabbitMQ as JSON objects. While communicating with RabbitMQ and processing result objects is fairly straightforward, writing the necessary script may not be the most efficient use of your time.

In this series, we ask our developers to provide insights into features and optimizations that are not very visible on the surface, but have a lot of impact under the hood. For this edition, one of our engineers is going to talk about a new feature that automatically determines the optimal in-memory queue size for specific IPs and domain groups.

The External MTA IPs feature lets MailerQ use IP addresses available on a remote host for sending emails, as if they are available on the MailerQ host. This feature is useful when for example you are running MailerQ in a container, and the public IP addresses used for sending are on a different host. It can also be used to move traffic from one on premises MTA to another, without moving the IP addresses to the new host right away.

As the end of this turbulent year approaches, it's time for us to look back and reflect on what has happened. Despite the obvious limitations and changes that this year has brought upon us all, it's been busy as ever. Let's have a look at some highlights!

In this new series, we ask our developers to provide insights into features and optimizations that are not very visible on the surface but have a lot of impact under the hood. For this edition, our lead C++ engineer Michael van der Werve is going to talk about a recently introduced optimization for queueing messages on three different levels: per IP, IP Pool, and domain.

We just released MailerQ version 5.12. For this version, we wrote a custom authentication library that allows for multi-user support for SMTP authentication and access to the Management Console.

On Wednesday, November 11th, MailerQ is invited to the thirteenth edition of Validity’s “The State of Email: LIVE”. This is a recurring webinar series dedicated to empowering marketers with real-time data, best practices, and email program recommendations to help you get the most out of your campaigns.

This year, the Black Friday/Cyber Monday weekend is expected to be even busier than usual in terms of email traffic due to the shift to online commerce over the past year. While MailerQ was already super-fast, we now introduced a couple of changes that further improve throughput stability and performance under heavy load. This includes the introduction of a custom, asynchronous DNS library (DNS-CPP) under the hood that replaces the synchronous libresolv library. Additionally, we removed the ability to configure settings such as QoS for temporary queues and now optimize these values dynamically, so these can no longer be misconfigured. Furthermore, RabbitMQ publisher confirms were enabled (configurable by setting rabbitmq-throttle, which has default value 100). This prevents runaway backpressure on the outbox queue when under heavy load.

Log lines contain useful information about your message delivery, delivery errors and overall performance. Tracking and monitoring the information provided by log lines helps to identify and rectify any delivery problems, which is why they are a valuable asset in protecting your deliverability. Effective logging, however, can become quite challenging if you do not have the right logging standards in place and if you are restricted by your application output. MailerQ writes basic log lines to log files, but also logs JSON result objects to a results queue. This logging configuration has several added benefits for large senders, which we will discuss in this blog post.

In the past quarter, our R&D team has been busy working on all kinds of under the hood projects to further improve our solution. The most notable addition is the new Response Pattern action for automatically adding faulty recipients to the Suppression List upon a certain response. This gives you the option to ensure that you will never attempt to deliver email to known non-existent or bad addresses.

We just released version 5.9 of MailerQ, which introduces a couple of improvements.

Doppler is Latin America's leading email marketing software provider. Since their launch in 2006 they have managed to rapidly grow into one of the most well-recognized email marketing applications across the Spanish speaking countries. As their growth persisted over the years, they soon discovered that it became more challenging and time-consuming to keep their custom-built sending solution up to date with the latest requirements. In addition, the lack of tools and reporting of their custom MTA made it difficult to manage and maintain their deliverability. They found a more suitable solution with MailerQ, which offers them out-of-the-box features and extensive reporting necessary to manage their deliverability on the go and enables them to continue to thrive.

Today, we released MailerQ version 5.8.5. This version, besides various improvements, introduces three brand new endpoints for the REST API. These new endpoints will further aid automation, integration with third-party platforms as well as work towards headless deployment.

Sending traffic to non-existent or invalid destinations can hurt your performance and even damage your IP reputation. With MailerQ's Suppression List you can preemptively prevent unnecessary connections to bad destinations that have shown to be harmful for different reasons. In this blog post we'll discuss four different types of 'bad' destinations and explain how including these on your Suppression List can be beneficial to your email operations.

In version 5.8, we introduced the External MTA IPs functionality that enables users to set up NAT rules. These rules can be used to configure the MTA to send using public IP addresses of another server. Implementing this functionality required some under-the-hood changes in the way MailerQ loads and manages MTA IPs. A neat result following from this is that any new IP addresses that are made available on the server the MTA is running on, will instantly be available in the MTA for use as well. This means that if you’ve added new IP addresses to the server, you can assign them to messages, IP pools or IP warm-up schedules in a heartbeat without a restart!

There are various methods for submitting messages to your email delivery platform. The most popular and widely adopted is of course SMTP. However, injecting over an HTTP REST API is also gaining popularity as an alternative. In this post, we'll go over various injection methods and describe some of the pros and cons of each approach.

Email databases naturally degrade each year. If you think about it, this is not that surprising. Email addresses change, as well as the interests of your subscriber base. If you want to maintain a good sender reputation and deliverability rate, it is important to regularly maintain the quality of your email list by applying proper list hygiene. List hygiene is the process you undertake to ensure that the email addresses in your list consist of active and real subscribers that are ready to engage with your content. In this blog we'll discuss why it is so important to maintain proper list hygiene and what you can do to attain that.

Mark your calendars and save the date! MailerQ and 250ok are excited to announce the 2nd edition of the Global Sender Summit happening on May 14 in Chicago, Illinois! Join us for a gathering of the most serious and educated email senders in the world to discuss the latest technologies, strategies, and keys to success.

2020 has just started and it's a good time for us to reflect on what's happened in 2019. It has been a very busy year with a lot of exciting new developments. Let's take a look back at a few highlights!

Inbox Marketer (founded in 2002) is Canada's leading email marketing agency. An important part of what they do revolves around managing their client's deliverability. Maintaining a good deliverability for their rapidly growing customer base requires deliberate attention and proactive effort. Luckily, with the help of our mutual partner, Tekside.io, Inbox Marketer has managed to earn top honours in deliverability services. Having a Mail Transfer Agent (MTA) that provides detailed insights into the deliveries is essential in achieving this. However, the sending solution that Inbox Marketer previously relied on lacked data transparency. They found a more suitable solution with MailerQ which offered them out-of-the-box result processing and tools necessary to manage their client's reputation efficiently.

With the release of version 5.8, we're introducing several improvements including two new powerful features: Suppression List and support for external MTA IPs.

On the 7th of November, email industry professionals from around the world gathered in Amsterdam for the inaugural edition of the Global Sender Summit, a one day conference with the most serious and educated email senders to share their knowledge and experience with their industry colleagues.

The latest news in the land of email fraud: "A new real estate email scam has cybercriminals cashing in. Losses have soared [...] to $1.3 billion last year." - (CBS Evening News, September 25 2019). Unfortunately, these types of messages are not uncommon. In fact, as time goes on and more of our data gets stored online, phishing and email attacks are only increasing - with drastic consequences. It is more important than ever for senders to put the right email authentication in place to minimize these attacks. The newest addition in email authentication is created to help with this: BIMI (Brand Indicators for Message Identification). As other methods for email authentication, BIMI does not only prove the legitimacy of the sender but also helps to improve deliverability. In this blog post, we'll take a closer look at what it is and how it works.

Last week, we released MailerQ version 5.6.4 which, after the introduction of our REST API in the previous version, now includes a new endpoint for setting, removing and getting forced errors. In case you don't know what a forced error is in MailerQ: with this functionality, you can fail individual deliveries including error code and description based on a combination of sending IP or IP Pool, target domain, and tags (many-to-many labels, used for identifying individual or organized deliveries such as "campaign_X", "customer_Y" or "transactional").

We rolled out an initial version of our REST API in which we introduce two endpoints for injecting messages and pausing/unpausing ongoing deliveries.

In this blog post, we will dive deeper into the world of bounces, one of the most important - and maybe most frustrating - terms in understanding your email delivery. A bounce is an automatic reply that you receive when your email can not be delivered to the recipient's mail server. There are many possible reasons for why an email message is rejected, for instance when an email address is invalid or disabled. As an email sender, it is important to analyze and understand these bounce messages as they can give you an insight into the reasons for your delivery error. Failure to do so can harm your sender reputation and, in turn, your email deliverability.

One of our favourite tools in MailerQ is tags. With tags, you can do a lot on an individual delivery level - or on any level of detail that you desire really. First, let me quickly explain what tags are and how they are used.

We are excited to announce the latest version of MailerQ - version 5.5 - which includes improved insights into deliveries that are scheduled to be retried, as well as new powerful ways of matching messages in the Rewrite Rules, and several performance enhancements. A closer look at the biggest improvements in MailerQ 5.5:

April has been a busy and exciting month for MailerQ. Last week we attended the CSA Summit in Cologne where we held a workshop on the interplay between senders and receivers' MTAs. Today, we are happy to bring to you MailerQ Version 5.4 which includes two new highly anticipated features that will further aid to improve your deliverability and sending practices: IP Pools and MX Pattern Grouping.

Billions of emails are sent around the world each day. Some of these successfully land in the recipient's inbox, while others never see the light of day. In fact, about 85% of the email traffic worldwide accounts for spam (Number from March, 2019). As a sender of email, you inevitably want your emails to end up in the inbox. Unfortunately, there is no magical spell that ensures they will end up there. Instead there are many factors that affect email delivery. One of these is your email reputation, which we will discuss in this post.

On the 10-12th of April, MailerQ will be attending the CSA Summit in Cologne. The CSA Summit is an event where international experts will support marketers and technical experts through a wide range of inputs on the topic of email.

When you use a new IP address to send out emails, mailbox providers can initially be hesitant to accept large volumes of email from it. Therefore, it is important to gradually increase your sending speed and volume, a process also known as IP warmup. This process allows mailbox providers to identify you as a legitimate sender. Warming up an IP address will minimize deliverability issues and maximize the results of your email campaigns.

Last week MailerQ attended the 44th M3AAWG meeting in Brooklyn, New York. The M3AAWG Meeting is a members-only event in which leading industry experts, researchers and public policy officials address topics as spam prevention, email deliverability optimization, bot migration, social network abuse and pending legislation. We look back at an interesting 44th edition.

We are continuously working on improving MailerQ. This week, we are proud to announce the latest release of MailerQ, 5.3. This version contains a new feature that will help to optimize and ease your sending practices:

We are happy to announce the release of MailerQ version 5.2! MailerQ 5.2 includes two highly requested and exciting new features:

If you are attending the 44th M3AAWG General Meeting in New York City, join 250ok and MailerQ October 8 for a delightful evening of conversations and beverages; our treat!

Email throttling means limiting the number of emails you send to a (specific) domain. The receiving side often set limits on the number of messages or connections they accept. When an SMTP client opens a connection, the SMTP server typically responds with a 220 code, but in some cases, it may reject the connection. If too many connections are rejected, you might be (temporarily) blocked. This is why you should throttle your email.

The MailerQ team will be present at the upcoming 43rd M3AAWG meeting in Munich from June 04 to June 07. We send our team over to discuss email developments with industry colleagues and to expand both, their and our knowledge.

Freshmail - the Polish leading ESP - recently decided to move their entire sending operations over to MailerQ. We asked their CTO Wojtek Ptak how he has experienced that move and what he expects from it in the future.

We are happy and excited to announce MailerQ version 5.0. This new major release offers many, many changes and improvements over the previous 4.4.* versions. Our colleagues from SMTPeter and Copernica have been using this new version for the last couple of months and are very happy with the improved stability, speed and the better controls of the user interface, which makes us confident to bring this new version out to the general public as well.

Attendees of 42nd M3AAWG General Meeting, join 250ok and MailerQ for a delightful evening of conversations and beverages!

The MailerQ team will be present at the upcoming M3AAWG meeting, from the 2nd till the 5th of Oktober in Toronto, Canada. We send our team over to discuss email developments with industry colleagues, expand their knowledge and develop a network of interesting persons working in the field of IT, and more specific, messaging.

The team of MailerQ is attending the M3AAWG 40th General Meeting, held this time in Lisbon, Portugal.

We have released MailerQ version 4.3.1. This is a mainly a bugfix release that solves a number of issues that came to the light in version 4.3.0.

MailerQ 4.3.0 is out. This version contains only a couple of small changes compared to our previous 4.2.10 release. However, because some config file settings now have a different meaning, we decided to up the version number to 4.3.

The team of MailerQ is attending the M3AAWG 39th General Meeting, held this time in San Francisco, CA.

We have just released MailerQ 4.2.9 which contains, besides bug fixes, two new features: messages stored in the NoSQL databases can now be compressed and we support the "r=y" property in DKIM headers.

We brought out MailerQ 4.2.8 today. In this new version a couple of small issues have been fixed, and we've added a new feature: MailerQ now automatically recognizes when a SSL certificate or the license file is updated. It is no longer necessary to restart MailerQ when such changes are made.

Today we brought out version 4.2.7 which fixes an issue with parsing incoming DMARC reports. In the previous 4.2.6 release we made MailerQ more tolerant in recognizing non-standard incoming DMARC reports. However, this earlier fix caused MailerQ to no longer recognize specific "normal" reports. This has now been fixed.

MailerQ 4.2.6 has been released with a couple of important bug fixes, and some nice new features. We recommend to upgrade to this version. The database structure has not been altered, and the format of the JSON messages is also the same, so you will not have to modify your applications or scripts to deploy version 4.2.6.

During the Christmas holidays we've been working on improving the recognition of incoming DMARC reports. An improved algorithm has been implemented and will be available in the upcoming version of MailerQ.

We have brought out MailerQ 4.2.5. This release fixes the compression inconsistency that we described a couple of days ago, as well as some small changes in the management console.

In the latest release of MailerQ, we've introduced a feature to compress the data that is sent through RabbitMQ. We sadly made a mistake with the implementation. We therefore advise you not to use compression yet, and wait for the upcoming bugfix release.

We've released version 4.2.4 of MailerQ. This release contains a couple of bug fixes, and two new features that we already announced yesterday.

The upcoming version of MailerQ - the expected version number is 4.2.4 - will have two small (but nice) new features. The communication with RabbitMQ can be gzip compressed, which brings down the amount of data that is sent over the internal network between MailerQ and RabbitMQ, and the retry intervals are no longer hardcoded, but can be configured in the config file, or on a per-message basis in the JSON.

We've removed the discussion forum from our website, because we found out that we sometimes overlooked questions.

We've released version 4.2.1 of MailerQ. This release solves a couple of issues that were reported for version 4.2.0.

It's with great pleasure that we release version 4.2 of MailerQ to the world. We have implemented a couple of useful features in this release and made various tweaks to the interface.

The MailerQ team has implemented the new ARC technology in MailerQ. This means (in short) that you can now modify emails that already had a digital signature (like a DKIM signature), and let MailerQ add an ARC signature to the message. The mail can then be forwarded to the recipient with this extra ARC signature.

The MailerQ team is going to attend the next M3AAWG meeting in Paris. If you are around and want to meet the MailerQ developers or representatives of the commercial team, please drop us an email so that we can make an appointment.

We're happy to announce version 4.1 of MailerQ. This new version features a couple of bug fixes, as well as a couple of interesting new features.

Today we have brought out version 4.0.3 of MailerQ that fixes a number of issues reported by our users. We recommend to upgrade to this new version.

After yesterday's 4.0.1 update, we bring out a new minor update today with a small number of additional fixes based on feedback from our users. We recommend upgrading to 4.0.2.

We've brought out MailerQ version 4.0.1 that fixes a couple of small problems that we found in MailerQ version 4.0.0. If you already use version 4.0.0, we recommend upgrading to 4.0.1.

We're proud to announce MailerQ 4.0. The latest version of our MTA, with more features than ever before. Please check our documentation for a list of everything that is new or has been updated. A lot has been changed:

As of today, we also offer daily development builds for MailerQ. If you want to have a sneak preview of the upcoming version of MailerQ, or if you want to test whether a certain bug has already been fixed or a new feature been introduced, you can fetch the latest development version of MailerQ from our repository.

Copernica, the company behind MailerQ, visited the 36th general meeting of M3AAWG in February 2016. During this event we had the opportunity to meet some of our users and to get valuable feedback on our MailerQ product, as well as suggestions for future improvements.

We are proud to announce version 3.0 of MailerQ. This brand new release of our powerful MTA brings many new features, changes and improvements. The biggest change is the move away from external libraries for MIME processing and altering. MailerQ now does own MIME processing based on the official email RFC's, which allows us to introduce all kinds of new features for email filtering and processing. 

MailerQ version 2.1 comes with a completely updated and more powerful plugin API, and a couple of other (relatively small) changes and improvements. We recommend all users to upgrade to this new version. But be careful: if you use the MailerQ plugin API, you may have to update your current plugins before you can upgrade.

Yesterday we brought out version 2.0.1 of MailerQ, and today we've released version 2.0.2. In both releases we fixed a couple of bugs that we encountered when dealing with incoming SMTP traffic.

Today we released MailerQ version 2.0, a version that has some very big changes and an awesome new feature: Copernica's Responsive Email algorithm has been embedded into MailerQ. We have also added SMTP-authentication by username and password, made improvements to the log files and renamed the "body" and "keepbody" property (for backwards compatibility "body" and "keepbody" are still accepted)

MailerQ version 1.1.3 has just been released. Two new features have been added to MailerQ in this release: DKIM keys can now also be used for other domains, and it is now possible to override the EHLO/HELO domain name that MailerQ uses for sending out email. Besides these two new features, several bugs have been fixed.

This is mainly a bug fix release that solves a few issues that did not make it into the release of version 1.1. We highly recommend upgrading to this new release, as some of these bugs might make your system vulnerable for abuse.

MailerQ version 1.1 has been released. This is a major update that adds a new 'smarthost' feature, which allows you use MailerQ in combination with an SMTP-relay. We also added a plugin architecture, which allows you to extend the functionality of MailerQ by building your own 'plugins'.

Update 1.0.6 of MailerQ has been released. This is a bugfix release and fixes a bug in regex flood patterns.

It's been a busy few weeks, MailerQ 1.0.5 is an important security update that disables the usage of SSLv3 in the webinterface. Make sure to update when you can.

It's been a busy week. We've just released MailerQ 1.0.4 only 2 days after MailerQ 1.0.3. Those two releases bring several improvements and bug fixes.

MailerQ users will no longer be redirected to Copernica.com to complete their payments. The entire payment process now takes places on the MailerQ website. We also updated the log-in process, so you might have to reset your password in order to log in.

You have probably noticed that we have completely changed the look and feel of the MailerQ website. We've added some new profile options and have improved the documentation. Find out what's new below.

We've just released MailerQ 1.0.2 This is an important update, an error in the 1.0.1. algorithm for domain groups caused hash collisions. This resulted in a lot of 'relay denied' errors.

We have just released MailerQ 1.0.1. This release brings several new features and bug fixes. There currently are some problems with registering on the website and creating a license. Please contact us at info@mailerq.com if you want to register or buy a license. These problems will be fixed in the coming week. Find the complete list with updates below.

It is finally here, the 1.0 release of MailerQ! We are confident in MailerQ's performance and stability and have decided to officially release MailerQ. This does not mark the end of development; we will continue to work on MailerQ and you can still expect frequent updates and improvements.

Update: this license structure is no longer supported.

We are pleased to announce the release of MailerQ 0.9.1 This release comes with several improvements and bug fixes:

Yes, you read that right! Only a week after the 0.8 release of MailerQ, we are proud to announce MailerQ version 0.9. Besides several bug fixes this version also moved the AMQP channels to seperate threads to make them run faster. We hope you enjoy our latest release! We will release version 1.0 soon!

We are pleased to announce the long awaited MailerQ 0.8.0 release of MailerQ. This version comes with a completely new interface, flood patterns and refactored code.

‘Anybody there?’ ‘Are you guys still working on MailerQ?’ ‘I like MailerQ, please don’t pull the plug on it!’ We’ve been getting a lot of people sending us tweets and emails, worried that we’d discontinue our services.

We are pleased to announce the release of MailerQ 0.7.4. This is a bug fix release, solving following issues:

Inside our MailerQ C++ application we've frequently used calls to 'dlopen()' - instead of using shared of static linking. There are a couple of good reasons why we've done this, which I'll explain in this article.

We are pleased to announce the release of MailerQ 0.7.3. We have spent last 5 weeks to fix known bugs before we move on to adding new features. This is mainly bug fix release, but we also implemented some new features.

In MailerQ 0.7.3 we have added support for MongoDB as a storage engine. However because of the fact that mongo-c-driver library API is not yet stable, current release works only with mongo-c-driver 0.7 and 0.7.1. To use MongoDB as a storage engine for MailerQ follow instructions below. First you have to install mongo-c-driver on your MailerQ machine as described:

If you do an upgrade from a MailerQ version 0.7.2 or earlier to a later version, the structure of the database is different than when you do a fresh install. This is not a problem, but if you like you can alter the database yourself to overcome this.

It has been 4 weeks since release of MailerQ 0.7.1, and we have been busy with improving the application and fixing bugs. Today we are happy to announce release of MailerQ 0.7.2. This is mainly bug fix release, but we also implemented some new features.

There was a bug in yesterdays release 0.7.0 which could cause MailerQ to crash occasionaly.

We are pleased to announce the release of MailerQ 0.7.0. Over last 3 weeks our development team worked on some new features, improvements and bug fixes. Let's have a look at them.

MailerQ version 0.6 brings a number of new features. It has been six weeks since version 0.5 and the development team has managed to use this time to fix some bugs and add new features.

RabbitMQ is a solid and and fast message queue, at Copernica we use it for queueing all kinds of messages throughout the application. Fast and flexible as it may be, it does come with a few quirks we've had to overcome. Over recent months, we've been moving more parts of our software to RabbitMQ, thereby increasing the load we place on RabbitMQ servers. In doing so, RabbitMQ started eating up far more diskspace than any sysadmin would be comfortable with (figures in excess of 20Gb overnight were no exception). Some research revealed that RabbitMQ would log every single connection attempt. When using persistent connections, this would, of course, not be a big problem. However, when you mostly employ short running PHP scripts that send tens of thousands of messages to RabbitMQ, you will find yourself wasting a lot of diskspace on what is essentially useless information.Luckily RabbitMQ has recently introduced some level of control over logging. Info level logs can be disabled by adding the following line to your /etc/rabbitmq/rabbitmq.config:

We have added support for PostgreSQL and Sqlite to MailerQ, as alternatives for MySQL that was already supported. And by doing so, we learned something about the differences between those different engines.