SMTP - 550 5.1.1 ... User unknown
Posted on 2011-05-03
I have a weird issue that is only affecting one user on my network. One my customers is trying to send a member of my customer service staff an email. Every the customer tries to send an email to this person he gets a bounce back that says:
----- The following addresses had permanent fatal errors -----
(reason: 550 Relay not permitted)
----- Transcript of session follows -----
... while talking to MX Record.:
<<< 550 Relay not permitted
550 5.1.1 <firstname.lastname@example.org>... User unknown
451 4.4.1 reply: read error from MX Record.
The weird thing is that my customer can send an email to anyone else in my customer service staff. its only affecting email@example.com. Any ideas? My customer can send an email to firstname.lastname@example.org just fine. Both email accounts are on the same server.