MX record for our domain points to dyndns.com, where upto 50 MB messages are received. From dyndns setup is to push mails to a zimbra (postfix) server inside the corporate firewall, where in message limit is set to 5MB.
When incoming messages are more than 5MB, we are expecting some kind of notification - it can be bounce notification, email to admin or logging of such actions. Can you help, how to setup this? Or where in postfix logs can we look for error notifications?
Thanks alot for your time, and I hope i've asked the question correctly.