dovecot - Jun 2019 - Dovecot LMTP rejecting mail from address with apostrophe

Hi,

I have an OpenSMTPD / Dovecot installation on an OpenBSD server. I recently came
across an issue where Dovecot LMTP would reject a message sent to a local user
from an address which contains a single apostrophe (e.g.
firstname.o'lastname at example.com). Apparently apostrophe, as well as a
number of other special characters, are valid characters in the local part of
the email address (that's everything to the left of the @ character).

The message I get in the logs is: 

Jun 14 11:57:34 atlantic smtpd[42606]: 21749fd12ac76b57 mda delivery
evpid=56aed6237d6444a0 from=<firstname.o'lastname at example.com>
to=<me at example.org> rcpt=<me at example.org> user=me delay=0s
result=PermFail stat=Error ("mail.lmtp: LMTP server error: 501 5.5.4
Invalid FROM: Invalid character in localpart")

where example.com is external domain and example.org is a local one. 

The part of the message: LMTP server error: 501 5.5.4 Invalid FROM: Invalid
character in localpart is returned by dovecot-lmtp. I?ve had a brief look at the
source code, and it seems the responsible code is somewhere inside
src/lib-smtp/smtp-address.c and, if I understand the code correctly, the address
parsing in actually done in src/lib-smtp/smtp-parser.c.

My question is is there a configuration option, similar to auth_username_chars
which lists valid characters in the email address, to stop Dovecot LMTP from
rejecting such emails? or maybe you know another way of getting it to accept an
email from such address?

My dovecot version is:

$ dovecot --version
2.3.5.1 (7ec6d0ade)

And in case that makes any difference, I'm running OpenBSD 6.5 patched to
005_libssl.

Thanks!
Mike

-- 
Michal Krzysztofowicz
http://beautifulocean.org/

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Am 14.06.19 um 16:20 schrieb Michal Krzysztofowicz via
dovecot:
> Jun 14 11:57:34 atlantic smtpd[42606]: 21749fd12ac76b57 mda delivery
evpid=56aed6237d6444a0 from=<firstname.o'lastname at example.com>
to=<me at example.org> rcpt=<me at example.org> user=me delay=0s
result=PermFail stat=Error ("mail.lmtp: LMTP server error: 501 5.5.4
Invalid FROM: Invalid character in localpart")
That's essentially the same bug as mentioned in 
<6386018f-22b2-9562-b5a2-36e81cbe2892 at debian.org> (bounces on invalid 
UTF-8 in localpart) that got assigned DOP-1045. Dovecot LDA and LMTP 
should just not care about remote address validity when delivering 
locally. It's not the LDA's business.

> On 14 Jun 2019, at 17:01, Daniel Lange <DLange at debian.org> wrote:
> 
> Am 14.06.19 um 16:20 schrieb Michal Krzysztofowicz via dovecot:
>> Jun 14 11:57:34 atlantic smtpd[42606]: 21749fd12ac76b57 mda delivery
evpid=56aed6237d6444a0 from=<firstname.o'lastname at example.com>
to=<me at example.org> rcpt=<me at example.org> user=me delay=0s
result=PermFail stat=Error ("mail.lmtp: LMTP server error: 501 5.5.4
Invalid FROM: Invalid character in localpart")
> 
> That's essentially the same bug as mentioned in
<6386018f-22b2-9562-b5a2-36e81cbe2892 at debian.org> (bounces on invalid
UTF-8 in localpart) that got assigned DOP-1045. Dovecot LDA and LMTP should just
not care about remote address validity when delivering locally. It's not the
LDA's business.
Ah, thanks a lot for that. I was trying to find any information about that, but
couldn?t really (perhaps my google-fu isn?t that great)!

Would you know if Dovecot project uses an issue tracker which is publicly
available, and which I can check? I didn?t see Issues section on the GitHub page
with the repo..

Thanks again!
Best Regards,
mike

-- 
Michal Krzysztofowicz
http://beautifulocean.org/

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