How to fix the slow email sending speed in Mautic?

Last Updated, 2020-02-28 mautic


Mautic is a feature-packed marketing automation platform that enables organizations of various sizes to send email communications at a large scale, it provides email template customizations and email flow. Mautic helps teams track email actions, optimize and replicate campaigns, and report on email status. Mautic also provides various other options to the user such as segmentation and automation which makes it one of the most popular email marketing tools available in the market.

With this, there might be some times that you might have experienced Mautic being too slow in sending emails, even when Mautic provides a huge advantage as a free service for email marketing, it will be very frustrating if the emails that are being sent at a considerably slower pace. Here we will try to fix those issues that might be causing delays in email transfers by looking at some potential issues.


  • A working Mautic setup
  • Integration with your email service providers SMTP or API endpoint

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Step 1: Email delivery configuration (for a small email list)

If your email list is comparatively smaller than in thousands, you can set your email delivery configuration to send the email immediately rather than in queue.

Delivery in a queue is usually done for a large batch of lists and usually waits for the send email Cron to start sending emails from the queue. You can eliminate the slow start of sending an email trigger by avoiding it altogether and sending the email immediately.

To check this option follow these steps

  • Login to your dashboard
  • Click on the gear icon beside your user profile in the navbar, this will open a vertical navbar on the right
  • Click on the [Configuration] option
  • In the Configuration panel click on [Email Settings]
  • Here you will find How should email be handled option
  • Select Send immediately option if it is not selected
  • Click on apply


Step 2: Send Email via API

This option will be limited to some people since there are some Email service providers that have API integration on Mautic and some don't.

Depending on that if you do have your service provider providing API integration and you are on SMTP integration, switching to API will have a considerable difference in email sending speeds since with SMTP the email is being sent to the SMTP endpoint one at a time but with API it can send a larger batch of emails at a time increasing the email send frequency.

To check this option you follow these steps

  • In your user dashboard click on the gear icon beside your profile
  • Select [Configuration] from the menu
  • Click on Service to send mail through dropdown to see the options
  • Depending upon your service provider you can check if the integration is through API or SMTP
  • To check that you have to find the option API Key after selecting the dropdown, if this option is visible then it is an API integration


Step 3: Increase your system specs

This is an obvious option to set, since processing millions of emails does take more memory, increasing system RAM will surely affect the number of processes the system can execute at a time.

The official recommended minimum system requirement for Mautic is 2 CPU and 4GB of available RAM per CPU core. If you are using a cloud server, it will be a lot easier to scale with those.

Step 4: CRON time intervals

Mautic uses Cron Jobs to execute its processes. Processes such as Segment update, Campaign Update, Campaign Triggering, Sending of Queued emails and much more are handled through your Cron intervals. And it is officially recommended that no two Crons should start at a time.

Since updates and triggers are crucial to be executed one after another it is recommended that the Cron intervals should be run in different intervals, email updates and Sending of emails wouldn't be done in an efficient way and might result in a delay in necessary executions.

To get detailed info about Mautic Cron jobs please follow this article.

Step 5: Use Database Caching

Database caching caches the select query along with the result set, which enables the identical selects to execute faster as the data fetch from the in-memory.

Since Mautic uses MYSQL for most of it's queuing and processing, it will be a boost to the Mysql query processing to use query caching for Mautic.


There is no direct way of increasing the email sending speed of the Mautic campaigns immediately but with this tutorial, some of these configurations can be done so as to get the most out of your Mautic installation.