Hello Paul, i come from here https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=265395 The echo in a mailbox with affected mails sounds like this, for one mail: string(5) "+0200" string(2) "UT" Mailheader looks like this, hopefully i guessed the right headers: for mail@example.com; Fri, 30 Sep 2016 18:41:57 +0100 (BST) and Date: Fri, 30 Sep 2016 17:41:57 UT Looks like some mua format their header like they want.