Is the POP3 server the UW ipop3d server?
Are the IMAP and POP3 servers from the same build? RH made changes which
cause non-interoperability between different builds. Make sure that both
the IMAP and POP3 servers come from the same build, or use vanilla UW
distribution instead of RH's hacked version.
Suggest that you read "Managing IMAP", by Dianna Mullet & Kevin Mullet,
published by O'Reilly, ISBN 0-596-00012-X, before doing this step.
It gives a good comparison of the UW and Cyrus servers. The target user
communities for the two have very little overlap. Cyrus is good if you
have a standalone server with no need to use or interoperate with legacy
-- Mark --
Science does not emerge from voting, party politics, or public debate.
Si vis pacem, para bellum.