I have been using courier for quite a while for 4 incoming mail servers with several thousand mailboxes using authdaemon/authmysql.
I recently upgraded a machine (reinstalled the OS, reinstalled same version of courier as before, with same settings) and with only a new disk subsystem / kernel, I now get this error on the secondary incoming mail servers (they use NFS to mount the mail users' home directories)
System error - unable to forward message.
This occurs when the forwarding address specified in the .courier file is rejected.
The current version of Courier provides additional diagnostic messages in this situation, now.
pgp00000.pgp
Description: PGP signature
