[MM3-users] How to increase maximum size of the message in mailman

Hi Team,

       I am currently running Mailman 3 with version 3.3.1 and in-built

postfix version 2.10.1-6 on RHEL 7.5 with PostgreSQL 11.7 version with default values. I am almost running 2200 lists with 128 GB RAM and 24 Cores on a single VM and on which all the mailman 3 components are running. I have been running this setup in production for the past 2 years and 6 months.

       I have recently encountered a scenario where a user sent mail

with a PPT attachment to one of the lists on the said mailman server. The mail is received by postfix on the mailman server and is handed over to mailman at *0.0.0.0:8024 <http://0.0.0.0:8024>.*

       But the /var/log/maillog says the below error during the above

hand shake.

*status=bounced (host 0.0.0.0[0.0.0.0] said: 552 Error: Too much mail data*

       I have browsed google for understanding and fixing the issue.

During which I encountered the information given by Mr. Mark Sapio at https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/thread/G.... But I could not fix the issue as it is mentioned the default size limit is 33554432.

I request someone to suggest where I can customize the value 33554432 and put a higher value or can be configured without any limit. I have configured message_size_limit as 100MB at postfix level. I would like to configure, in fact, the same at mailman level too. But I don't understand where to edit.

I tried editing the variable DATA_SIZE_DEFAULT value in /var/lib/mailman/mailman/.tox/py36-nocov/lib/python3.6/site-packages/aiosmtpd/smtp.py file but unfortunately no luck.

So, could someone please help us in this regard ?

Also, please also let me know if there is any limitation specific for the attachments so that I can customize that too respectively.

Thanks & Regards, Shashi Kanth.K 9052671936