Dear All, I maintain several systems running ispconfig2. One of the older ones is running CentOS 4.8. Recently users have started to complain about the occasional inability to connect to the POP/IMAP server. These occasions are momentary and generally last only a short time however the instances have become more frequent as more users are added. I've dug through logs and read through quite a bit of commentary on issues like this. From what I understand this could be related to worker threads authenticating users via pam. It seems the simplest way to resolve is to upgrade to dovecot version 1 or later. Anyone have any idea if this can be safely done without breaking existing functionality? The server in question is configured for maildir. I know that ispconfig2 works fine with dovecot 1 as in centOS 5 but I'm unsure of the effects of upgrading on ispconfig previously installed with dovecot 0.99. The caveats on upgrading are described here: http://wiki.dovecot.org/Upgrading/1.0 I wonder about the change in POP3 UIDLs and other such items mentioned. Would be interested in hearing from anyone who could shed light on this or who has attempted such an upgrade. Thanks in advance.