# ps waux | grep imap
# ps waux | grep dovecot
Apr 30 04:50:20 sv1 dovecot[16032]: auth(default): passwd(admin,127.0.0.1): Password mismatch
Apr 30 04:50:20 sv1 dovecot[16032]: auth(default): passwd-file(admin,127.0.0.1): no passwd file: /etc/virtual//passwd
Apr 30 04:50:21 sv1 dovecot[16032]: pop3-login: Disconnected: user=<admin>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured
try resetting the password; the error message seems fairly obvous.
Jeff