I've noticed a burst of about 12000 of these mbox-rewrite msgs in the log, spread over about 10 minutes. They are always for the same person (XXX'd out here), and have not occurred before or since. There's no evidence of device problems in the message log. Jan 10 17:46:43 ls1 imap-login: Login: XXX [::ffff:10.2.0.1] Jan 10 17:46:43 ls1 imap(XXX): file mbox-rewrite.c: line 429 (mbox_write_header): assertion failed: (hdr_parsed_size.physical_size == hdr_size) Jan 10 17:46:43 ls1 dovecot: child 6004 (imap) killed with signal 6 Jan 10 17:46:43 ls1 dovecot: child 6006 (imap) killed with signal 6 Jan 10 17:46:43 ls1 dovecot: child 6008 (imap) killed with signal 6 Jan 10 17:46:43 ls1 imap-login: Login: XXX [::ffff:10.2.0.1] Jan 10 17:46:43 ls1 imap(XXX): file mbox-rewrite.c: line 429 (mbox_write_header): assertion failed: (hdr_parsed_size.physical_size == hdr_size) Jan 10 17:46:43 ls1 imap-login: Login: XXX [::ffff:10.2.0.1] Jan 10 17:46:43 ls1 imap(XXX): file mbox-rewrite.c: line 429 (mbox_write_header): assertion failed: (hdr_parsed_size.physical_size == hdr_size) Jan 10 17:46:43 ls1 imap-login: Login: XXX [::ffff:10.2.0.1] Jan 10 17:46:43 ls1 dovecot: child 6010 (imap) killed with signal 6 Jan 10 17:46:43 ls1 dovecot: child 6012 (imap) killed with signal 6 Jan 10 17:46:43 ls1 imap(XXX): file mbox-rewrite.c: line 429 (mbox_write_header): assertion failed: (hdr_parsed_size.physical_size == hdr_size) Do I need to worry? I'm still using dovecot-0.99.11-4 on a RHEL4 Opteron box. Cheers, Terry.