kopano-lmtp no 8BITMIME support

After an update to 8.6.80 I can see the following in my syslog:

postfix/lmtp[3042]: host 127.0.0.1[127.0.0.1] offers SMTPUTF8 support, but not 8BITMIME

Has 8BITMIME support been removed of kopano-dagent, or is it something to configure?

Thanks, but thats another topic. It’s about kopano not supporting SMTPUTF8 but my question is about supporting 8BITMIME

@klausf said in kopano-lmtp no 8BITMIME support:

Has 8BITMIME support been removed of kopano-dagent

No, kopano actually never supported 8bitmime, but that has only become obvious after preliminary smtputf8 testing through https://stash.kopano.io/projects/KC/repos/kopanocore/commits/30c0b8d58be7779bb7b9d9c22293f371a27a1c2f and https://stash.kopano.io/projects/KC/repos/kopanocore/commits/0c808bf09166b8c557e303daef46723ef1714e7c

According Jira ticket is https://jira.kopano.io/browse/KC-833

So what’s wrong? Postfix, who says that if an LMTP Server could do SMTPUTF8, should also be able to do have 8BITMIME support. Actually, the smtp extension 8BITMIME has been standardized in 1994 and postfix is rightly surprised.

To avoid such messages kopano should also support older smtp extensions like 8BITMIME. Your linked ticket does not cover this topic and the above error message.

@klausf said in kopano-lmtp no 8BITMIME support:

So what’s wrong?

The code that triggers this message is located at:
https://github.com/vdukhovni/postfix/blob/master/postfix/src/smtp/smtp_proto.c#L654-L664

Its simply there to inform the admin that postfix won’t relay a message formatted as 8bitmime.
The way I understood the developer there is little to no use for us in implementing 8bitmime.

Can you name an instance where the non availability of 8bitmime lead to a non deliverable message?

In the code you linked, there is a statement of the postfix developer:


Our primary mission is to deliver mail, not to force people into compliance

Obviously it is RFC (?) conform to support 8BITMIME when SMTPUTF8 is offered by a mailserver. So it should be implemented?

I don’t know any case where a mail could not be delivered because I don’t always look at the logfiles of my supported servers.

If postfix decides not to force others into compliance, why do you want to? ;-)

Anyways if it’s important to you we’ll gladly accept a patch.

Not to force does not mean that the software should not comply with the rules. So I would like an adjustment of the Kopano code.
Maybe ask a Kopano developer to contact the developer of the Postfix patch to check the need for customization. Would that be possible?
I am not a programmer and therefore can not contribute a patch. I can only try to detect and report anomalies in the software and hope that my contribution will be helpful to further improve it.

@klausf said in kopano-lmtp no 8BITMIME support:

So what’s wrong? Postfix, who says that if an LMTP Server could do SMTPUTF8, should also be able to do have 8BITMIME support. Actually, the smtp extension 8BITMIME has been standardized in 1994 and postfix is rightly surprised.

To avoid such messages kopano should also support older smtp extensions like 8BITMIME.

imo, softeware developers MUST obey RFC in the software, but how users setup it up to them.
Personal, im obligated by law to setup conform RFC for some settings. ( hostnames, helo hostnames, A-PTR-MX setups )

Whats wrong here.
Imo, in RFC 6532 there is a the relaxed restriction on MIME rfc2046 and the “f.-up” here is, the RFC ASUMMES… that newer systems have here UTF8 and 8BITMIME supports in newer systems.
For postfix, this is correct, for Kopano not.
see; https://tools.ietf.org/html/rfc6533 Chapter 4.4 second alinea.

This is why i suggest that kopano should have added this to the manual that postfix 3.x enables UTF8 by default.

In a last version this didn’t happen anymore. But in the current version everything was like before:

postfix/lmtp[3137]: host 127.0.0.1[127.0.0.1] offers SMTPUTF8 support, but not 8BITMIME

Package: kopano-server
Source: kopano
Version: 8.6.80.1350-0+212.1

@klausf said in kopano-lmtp no 8BITMIME support:

In a last version this didn’t happen anymore. But in the current version everything was like before:

can you specify what you mean with “in a last version”?

I was going too fast and I missed the logs, sorry. There were no changes in previous versions. Is the topic being worked on or is there a bug report?
Thanks!

@fbartels said in kopano-lmtp no 8BITMIME support:

If postfix decides not to force others into compliance, why do you want to? ;-)
Anyways if it’s important to you we’ll gladly accept a patch.

I already wrote the following in this thread about this. Its not a priority for us, but if you want to contribute something patches are welcome.

As I already wrote in:

https://forum.kopano.io/topic/1486/kopano-lmtp-no-8bitmime-support/11
I am not a programmer and therefore can not contribute a patch. I can only try to detect and report anomalies in the software and hope that my contribution will be helpful to further improve it.

Did you read the suggestions of thclo in his post in
https://forum.kopano.io/topic/1486/kopano-lmtp-no-8bitmime-support/10 ?

Have you noticed there’s already a patch from jengelh in his post:
https://forum.kopano.io/topic/1486/kopano-lmtp-no-8bitmime-support/12

Have you tested the patch, or should I file an officially bug report for this?

@klausf said in kopano-lmtp no 8BITMIME support:

Have you noticed there’s already a patch from jengelh in his post:
https://forum.kopano.io/topic/1486/kopano-lmtp-no-8bitmime-support/12

well if that would have fixed it, you should not see the message anymore.

I’m still convinced that we have no benefit from implementing this and you did not bring up any argument to convince otherwise. But we are running in circles here and therefore I’m closing this thread.

  • thanks for this hint! we are aware it is not 100% conform with RFC.
  • we do neither see nor can imagine any impact on e-mail-delivery with Kopano now and did also not see any example in this thread.
  • it is time-consuming to add & QA features so we have to decide on what to do when
  • I created issue the https://jira.kopano.io/browse/KC-1238 in Jira for this
  • the solution for now is that we have just added to the dagent that he will announce that he supports 8BITMIME, if such emails are actually delivered without issues remains to be seen.
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