On 9/3/21 5:51 PM, Christian Buser via Mailman-Users wrote:
Hi all
I am using Mailman in a cPanel instalation - Mailman 2.1.33 on cPanel 98.0.6 - and occasionally receive an error message like the one below:
address@domain.ch host mx01.servicehoster.ch [194.191.24.200] SMTP error from remote mail server after end of data: 550 Headers contain illegal byte order mark (BOM) Reporting-MTA: dns; my.provider.eu
This happened today with 5 (of about 150) subscribers on 2 receiving servers, but only every few days - not for every message. The message for which these complaints had been received today have a header line "X-Mailer: iPhone Mail (18G82)", but I think I have also seen others before.
So far I could not yet find out why these messages are refused by the receiving server, it could be a Mailman issue or an issue of the mail program used by the author of the message.
Any ideas what could be done to prevent these errors?
Thank you, Christian
Basically the mail program being used is broken and is putting an illegal character in the message.
Headers are supposed to be just plain ASCII unless an extention is negotiated, but even then, there is no reason to send a BOM, as even when utf-8 is used, there is still no 'byte order' to worry about.
This is definitely NOT a Mailman issue, but an MTA issue, as that is where the error is being generated.
It might be possible to configure your MTA to be more forgiving, but it really looks like the sender is bad.
--
Richard Damon