Environment:
GroupWise 18.3.x

Situation:
After upgrading to GroupWise 18.3.x, the Administrator is receiving email notifications stating:
D030-No host number for status errors
Type of message: DELIVERED status

In the verbose POA log, will see entries like this:

13:48:57 F8ED Processing 50e45f49.001 Message ID(60E4976F.444:64:23510)
13:48:57 F8ED Sender of message (50e45f49.001) .GWIA.gwdom
13:48:57 F8ED Processing update: user status record
13:48:57 F8ED Error: No host number for status [D030]
13:48:57 F8ED Mailing Problem Message to Administrator
13:48:57 F8ED Begin distribution to 1 users
13:48:57 F8ED Distributed: Admin

Resolution:
Contact GroupWise support and request GroupWise 18.3.1 build 138338 or higher to resolve this issue.
Ensure that all domain and post office databases are upgraded to that build.

If upgrading is currently not an option, then temporarily disable DSN on the GWIA.
The DSN setting is located in the GWIA properties | SMTP/MIME tab | ESMTP Settings section.

Access support article here