The Problem: You send an email to someone and get the following back
Your message did not reach some or all of the intended recipients.
Subject: Any Subject
Sent: 6/4/2010 2:31 PM
The following recipient(s) cannot be reached:
This User on 6/4/2010 2:31 PM
Server error: ‘550 Requested action not taken: mailbox unavailable or not local’
The Cause: Both sender and recipient are on the same mail server, but the recipient’s mail server is hosted by Google Apps (or some other mail server). Your smtp server makes a preliminary request to the wrong server, and causes this false error message.
The Solution: The recipient (who has the mail server hosted by Google Apps) needs to disable mail services for their domain. You can do it in IIS directly (assuming you are running Windows). In Plesk simply go to Domains > Mail > Disable Mail
This post originally appeared on the Stronico blog – with the absorption of Stronico into Digital Tool Factory this post has been moved to the Digital Tool Factory blog