Exim v4.91: Cant Enable IGNORE_SMTP_LINE_LENGTH_LIMIT = 1 macro to allow long lines

Question

Ever since upgrading to Exim 4.91, legitimate email notifications are being rejected with an error "T=remote_smtp: message is too big (transport limit = 1)".

This appears to be related to a new ACL in Exim as described here to block messages that contain lines longer than 998 octets :

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=828801

A macro was supposedly added to v4.88~RC6-2, which disables this ACL named IGNORE_SMTP_LINE_LENGTH_LIMIT and to disable the ACL you can configure it to 1.

In my configuration, I have a server that sends email notifications. This server uses another server as a smarthost. I am running centos and have a config at /etc/exim/exim.conf on both servers.

I can't seem to disable this ACL no matter what I do.

I have added IGNORE_SMTP_LINE_LENGTH_LIMIT=1 to the top of both servers exim.conf files and continue to get errors.

Any suggestions on what to do?

Answer 1

I use "one big config-file" (not split-config), and adding

IGNORE_SMTP_LINE_LENGTH_LIMIT=1

to /etc/exim4/exim4.conf.localmacros works.

Answer 2

My configuration is also splitted in multiple files and uses a smarthost. Following these instructions, it works:

• Create a new file in acl directory with nano /etc/exim4/conf.d/acl/00_local and put this:

IGNORE_SMTP_LINE_LENGTH_LIMIT=1

• Reload configuration with systemctl reload exim4 or restart the service with systemctl restart exim4

Send an email and check the exim logs from /var/log/exim4/mainlog .