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
Christian Buser, Hohle Gasse 6, CH-5507 Mellingen (Switzerland) Hilfe für Strassenkinder in Ghana: https://www.chance-for-children.org
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
Christian Buser via Mailman-Users writes:
� 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
I generally agree with Richard about this. However, if I understand correctly, although your MTA is reporting this, it's the remote MTA that is rejecting the email.
It's possible that the remote MTA is correct in doing so, if the BOM is occurring at the beginning of a logical line in the header, including the first. In that case it's part of the field name, and that still has to be ASCII according to RFC 6532.
So far I could not yet find out why these messages are refused by the receiving server, it could be a Mailman issue
It's not a Mailman issue; there's nothing in Mailman that could introduce a BOM in UTF-8, except maybe your footer or header, or a bogus subscription address or display name. But any of those would cause all messages to be rejected, I suppose.
or an issue of the mail program used by the author of the message.
It could be. It could also be an MTA (yours or downstream) that translates a MIME word or transfer-encoded body to UTF-8 so it can use SMTPUTF8. In either of those cases, though, I believe the receiving MTA is non-conforming.
Any ideas what could be done to prevent these errors?
If it's not a downstream MTA doing something completely crazy, I'd want to know where in the message the BOM is found, and whether it's transfer-encoded or not when it gets to Mailman. It would be easy to write a BOM-stripper handler, but I would be uncomfortable stripping all of them (even though actual ZWNBSP is very rare, since that character has been generally deprecated in favor of U+2060 WORD JOINER). So I'd like to know where it causes problems.
Steve
participants (3)
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Christian Buser -
Richard Damon -
Stephen J. Turnbull