Added on Jun 18th, 2012 and marked as config mail postfix

By default the size limit of a message is set by Postfix at 10240000 bytes (roughly 10MB). You can check the actual message size limit with the following command:

postconf -n | grep message_size_limit

If no value is returned, then the default value is used. You can check this value with:

postconf -d | grep message_size_limit

To set the message size limit:

postconf -e 'message_size_limit = 104857600'

This will set the size limit to (roughly) 100MB.

Restart Postfix to activate the new size limit.