lda: Warning: Failed to parse return-path header: Invalid character in localpart

[Stephan Bosch]

Op 1/31/2018 om 10:44 PM schreef Christian Authmann:
> Hello,
> On 31.01.2018 22:35, Stephan Bosch wrote:
>> Op 1/31/2018 om 6:17 PM schreef Christian Authmann:
>>> Hello,
>>>
>>> Sometimes, when delivering mails, this warning appears in my syslog:
>>>
>>>> lda(...): Warning: Failed to parse return-path header: Invalid
>>> character in localpart
>>>
>>> dovecot-lda still exits with 0 and the mail is inserted into my inbox.
>>>
>>>
>>> Looking at the mails in question, I determined that the error is
>>> caused by a multiline Return-Path header. Here's a testcase:
>>>
>>> --- snip ---
>>> Return-Path:
>>>    <nowhere at example.com>
>>> From: "Nowhere" <nowhere at example.com>
>>> To: redacted at example.com
>>> Subject: Testcase for lda warnings
>>> Date: Wed, 31 Jan 2018 12:00:00 +0000
>>>
>>> This is a message body.
>>> --- snap ---
>>>
>>> Copy into a file, with \r\n line endings, then run something like this:
>>>> cat testcase.txt | /usr/lib/dovecot/dovecot-lda -e -d '<username>'
>>> with a username recognized by your running dovecot installation.
>>>
>>> The header is 'Return-Path:', \r\n, two spaces, '<...>', \r\n
>>>
>>> According to rfc2822 folding rules, that should be valid - the
>>> Return-Path header allows CFWS at that location.
>>>
>>>
>>> The error message originates in lib-lda/mail-deliver.c in
>>> mail_deliver_get_return_address(), while the invalid character message
>>> seems to originate from one of several places in lib-lda/mail-deliver.c
>>
>> This is Dovecot v2.3.0 right?
>>
>> Regards,
>>
>> Stephan.
>
> yes, 2.3.0 (c8b89eb), archlinux, x64. Sorry for not mentioning it
> earlier.

Whoops, yes, problem is obvious.

Regards,

Stephan.