Message has lines too long for transport - Exim Error Log

Question

You have received reports that emails are not able to be sent with "Message has lines too long for transport". How do I raise the SMTP length over 1000000?

Answer

Increase the message_linelength_limit in the Exim Basic Configuration Editor interface, or by manually editing the value for message_linelength_limit in /etc/exim.conf.localopts. You'll want to increase the value incrementally until you find a limit that works for you.

Additional Resources

Chapter 48 - Message processing

Exim Configuration Manager