and just so you can see the error in the mail log.
Code:
Feb 1 14:50:48 wci postfix/qmgr[3164]: 1AB0EAC1CF: removed
Feb 1 14:50:48 wci maildrop[4548]: Unable to open mailbox.
Feb 1 14:50:48 wci postfix/pipe[4547]: 72A5AAC1D8: to=<alexis@mydomain.com>, relay=maildrop, delay=0.13, delays=0.04/0.02/0/0.07, dsn=4.3.0, status=deferred (temporary failure. Command output: /usr/bin/maildrop: Unable to open mailbox. )