Groupwise 7.0.3 Gets 550 Blocked and Yahoo bulk treatment

[Mike021548141]

I know this is a old post by for reference a 550 is reported by the receiving MTA to the sending MTA i.e.

1) Your mail server (GWIA) connects to the remote mail server (say GMail MX server)

2) It follows the standard process for ESMTP e.g. ehlo domain.com, mail from: you@domain.com, rcpt to: them@theres.com etc...

3) While the GWIA is posting the ESMTP info and header info to the receiving server the receiving server takes whatever steps its configured for detecting and blocking SPAM mail

4) If the receiving server finds a reason to reject your email such as failing DKIM verification, failing SPF verification or being blacklisted (aka DNSBL or RBL) then it will report ESMTP error 550 to the sending server (your GWIA)

5) When your GWIA receives the 550 error message from the receiving server it stops trying to send the email, this saves traffic at both ends as it knows the email is not going to be delivered by the receiving server

6) The GWIA sends a NDR (Non Delivery Report) to you as the originator (author) of the email. This is why you are getting a error message from your own GWIA, however it is the receiving server that is blocking your email

So in short for some reason the receiving server is rejecting your email because it believes you are/have been sending spam. Top two reasons are,

1) A virus has infected one of your computers and is/has been sending SPAM

2) You have been blacklisted. Check if you are black listed, I suggest this web site
Email Blacklist Check - See if your server is blacklisted

MC