When a user logs on, the following messages appear in the log: dovecot: imap 21360 : Loading modules from directory: /usr/local/lib/dovecot/imap dovecot: imap 21360 : dlopen(/usr/local/lib/dovecot/imap/lib02_trash_plugin.so) failed: /usr/local/lib/dovecot/imap/lib02_trash_plugin.so: undefined symbol: quota dovecot: imap 21360 : Module loaded: /usr/local/lib/dovecot/imap/lib01_quota_plugin.so dovecot: imap 21360 : dirsize quota path = /shared/homes/rscweb.net/jpm/Maildir/ dovecot: imap 21360 : dirsize quota limit = 512000kB dovecot: imap 21360 : Module loaded: /usr/local/lib/dovecot/imap/lib02_imap_quota_plugin.so dovecot: imap 21360 : dlopen(/usr/local/lib/dovecot/imap/lib01_zlib_plugin.so) failed: /usr/local/lib/dovecot/imap/lib01_zlib_plugin.so: undefined symbol: gzseek Removing those files with rm -f lib01_zlib_plugin.* lib02_trash_plugin.so solves the problem. Platform Centos 4.2 , Linux 2.6.9-22.0.1.ELsmp Regards, -JP