Normally for a log line containing the contents of a Message-Id, it is logged like the following
Nov 29 11:41:27 xxx dovecot[211]: lmtp(lee)<30167><XXXXX>: sieve: msgid=<x...@example.net>: stored mail into mailbox 'Notifications' However, if there is CFWS other than a space, it changes the format of the log line (potentially making the logs harder to process - eg via “logcheck" rules) Nov 29 11:50:09 xxx dovecot[401]: lmtp(lee)<55724><XXXXX>: sieve: msgid=? <x...@example.com>: stored mail into mailbox ‘Notifications' A message-id line broken up is valid per RFC 5322 and header whitespace shouldn’t be significant for logging purposes https://tools.ietf.org/html/rfc5322#section-3.6.4 https://tools.ietf.org/html/rfc5322#section-3.2.2
