Environment
Novell GroupWise 2012 Support Pack 1
Novell GroupWise 2012 Support Pack 2
Situation
ERROR: "Error Listen Port is already in use. [856A]"
GWIA not listening on POP3 / port 110
GWIA not listening on HTTP / port 9850
GWIA not listening on IMAP / port 143
GWIA listens only on port 25
Resolution
If one of the ports that GWIA tries to start is in use, then GWIA fails to start POP3, IMAP and HTTP Port. SMTP Port 25 works just fine
For example, if POA is listening on Port 143 and IMAP is enabled on GWIA too, then GWIA will fail to start POP3 (110) and HTTP (9850) port too
Workaround Steps:
Make sure that the Port GWIA uses is not being used by some other application