Send Immediately vs. Queue

Your software v4.4.11
My PHP version is : 8.0
My MySQL/MariaDB version is (delete as applicable): MySQL/MariaDB version 10.5

Fairly large Mautic instance with 1.5 million contacts. A couple times a week my client sends 100k contacts to Mautic via API for an email campaign. We connect to PostMark via their API for sending emails. Mautic email config is set to “send immediately.” This results in 2500 contacts being submitted every 15 minutes, which results in 100k emails taking 15 hours to send.

Client wants to speed this up. Have confirmed PostMark is not a bottleneck, nor does it seem the size of the server.

2 questions:

  1. Should I have the email config set to Queue in Mautic and adjust the “message limit” amount and reduce the “time limit” amount to something like 5 minutes? Or does this matter in this instance?

  2. Is the 2500 contact limit via the API a Mautic limitation, a server limitation (or server setting) or a setting in the API call?

I read on the forum that adding the following to the API call can control batch numbers:


I manage the Mautic instance; their IT people handle the API but also have access to Mautic and the server.

Thanks for any help and/or clarification.

Chris Blair

Forget to ask, if adding the --batch[=BATCH] setting would help, where does that go? My IT guy said appears as if it would go in a PHP directive or file, like the Mautic config? I see that Mautic config has API rate limit options, but where would the —batch[=BATCH] setting go in that file??