Hi.
Groupwise 8 SP3 on Netware 6.5 SP8

We have been experiencing the occasional issue with "551 This is not a relay host - mail must be to or from host domain" or "550 relaying denied". A user will send an email, get the above message and then typically resend the email 5 or 10 minutes later and the second email will go through. We currently have a relatively new (about a year old, these errors have not been happening that long) Fortigate firewall in front of Groupwise.

This seems to happen when sending to email addresses that are hosted by a different domain name than what the email address shows.

Is this a misconfiguration on the receiving side or something on my side that I need to look at.? I have included the relevant portion of the GWIA log for a couple of examples below, and removed the user names.

Thanks,
Scott

11:54:24 0182 MSG 4007924 Analyzing result file: SLAVE/SYS:\GWISE\WPGATE\GWIA\result\r26e4ff6.126
11:54:24 0182 MSG 4007924 Command: benesh.com
11:54:24 0182 MSG 4007924 Response: 220 mail1.siast.sk.ca ESMTP ready at Mon, 28 Oct 2013 11:52:39 -0600
11:54:24 0182 MSG 4007924 Command: EHLO owzw.com
11:54:24 0182 MSG 4007924 Response: 250 ok
11:54:24 0182 MSG 4007924 Command: MAIL FROM:<sender@owzw.com>
11:54:24 0182 MSG 4007924 Response: 250 <sender@owzw.com> Sender OK
11:54:24 0182 MSG 4007924 Detected error on SMTP command
11:54:24 0182 MSG 4007924 Command: RCPT TO:<recipient@benesh.com>
11:54:24 0182 MSG 4007924 Response: 551 This is not a relay host - mail must be to or from host domain.
11:54:24 0182 MSG 4007924 Command: DATA
11:54:24 0182 MSG 4007924 Response: 221 closing connection. Goodbye!
11:54:24 0182 Building undeliverable message

09:09:27 0182 MSG 4007445 Analyzing result file: SLAVE/SYS:\GWISE\WPGATE\GWIA\result\r26e28d7.957
09:09:27 0182 MSG 4007445 Command: laurierhomes.com
09:09:27 0182 MSG 4007445 Response: 220 mta1111.mail.ne1.yahoo.com ESMTP YSmtpProxy service ready
09:09:27 0182 MSG 4007445 Command: EHLO owzw.com
09:09:27 0182 MSG 4007445 Response: 250 ok
09:09:27 0182 MSG 4007445 Command: MAIL FROM:<sender@owzw.com>
09:09:27 0182 MSG 4007445 Response: 250 sender <sender@owzw.com> ok
09:09:27 0182 MSG 4007445 Detected error on SMTP command
09:09:27 0182 MSG 4007445 Command: RCPT TO:<recipient@laurierhomes.com>
09:09:27 0182 MSG 4007445 Response: 550 relaying denied for <recipient@laurierhomes.com>
09:09:27 0182 MSG 4007445 Command: DATA
09:09:27 0182 MSG 4007445 Response: 221 mta1111.mail.ne1.yahoo.com
09:09:27 0182 Building undeliverable message