I have Debian - Postfix - Dovecot - Squirrelmail setup on my email server and I am perfectly able to send and receive email fine from Thunderbird with no issues.
When I login to Squirrelmail, I can read my email perfectly however when I try and send a message, I get the following message:
Command parameter not implemented
Server replied: 504 5.5.2 <192.168.0.100>: Helo command rejected: need
So basically it appears that when SM attempts to connect to the Postfix server, it is using a HELO command of its IP which does not conform to RFC 2821. I also have Postfix main.cf set to reject invalid HELO requests:
Does anyone know how I can resolve this issue and have SM web GUI properly submit a properly formatted HELO request when sending mail via Postfix?