UTF8 in from line???

[Claudio Junior]

Hey guys,

I have a curious case here which is a user sending emails using the google output server, which is being denied by my server. The error that is logged is:

Nov 16 18:36:48 srv04 postfix/cleanup[19091]: 5C1F31F8007D: discard: header From: =?UTF-8?Q?Andr=C3=A9_Luis_Vieira?= <***@kkk.kkk.kk> from mail -ua1-x92e.google.com[2607:f8b0:4864:20::92e]; from=<***@kkk.kkk.kk> to=<***@xxxxxx.xxx.xx> proto=ESMTP helo=<mail-ua1-x92e.google.com>

The email is not arriving at the destination, and an "error" is not being returned to the origin of the email. I did a test on the swan and got the following negotiation:

***@server01:~$ swaks --to ***@xxxxxxxx.xxx.xx --from ***@kkk.kkk.kk --server mail.xxxxxxxx.xxx.xx --header 'From: =?UTF-8 ?Q?Andr=C3=A9_Luis_Vieira?= <***@kkk.kkk.kk>'
=== Trying mail.xxxxxxxx.xxx.xx:25...
=== Connected to mail.xxxxxxxx.xxx.xx.
<- 220 srv04.xxxxxxxx.xxx.xx ESMTP
-> EHLO server01.yyyyyyyyy.yyy
<- 250-srv04.xxxxxxxx.xxx.xx
<- 250-PIPELINING
<- 250-SIZE
<- 250-VRFY
<- 250-ETRN
<- 250-STARTTLS
<- 250-AUTH PLAIN LOGIN
<- 250-AUTH=PLAIN LOGIN
<- 250-ENHANCEDSTATUSCODES
<- 250-8BITMIME
<- 250 DSN
-> MAIL FROM:<***@kkk.kkk.kk>
<- 250 2.1.0 Ok
-> RCPT TO:<***@xxxxxxxx.xxx.xx>
<- 250 2.1.5 Ok
-> DATE
<-354 End data with <CR><LF>.<CR><LF>
-> Date: Wed, 17 Nov 2021 10:18:49 -0300
-> To: ***@xxxxxxxx.xxx.xx
-> From: =?UTF-8?Q?Andr=C3=A9_Luis_Vieira?= <***@kkk.kkk.kk>
-> Subject: test Wed, 17 Nov 2021 10:18:49 -0300
-> Message-Id: <***@server01.yyyyyyyy.yyy>
-> X-Mailer: swaks v20181104.0 jetmore.org/john/code/swaks/
->
-> This is a test mailing
->
->
-> .
<- 250 2.0.0 Ok: queued as 7F4E31F8007D
-> QUIT
<- 221 2.0.0 Bye
=== Connection closed with remote host.
***@server01:~$


What can be done to resolve this? Is it a source or destination error?

Note: in order to protect the users, I put a mask over the domain names. Fighting against spam sucks!

Thanks

Claudio Jr.

[Bob Nichols]

Post by Claudio Junior
I have a curious case here which is a user sending emails using the
google output server, which is being denied by my server. The error
The email is not arriving at the destination, and an "error" is not
being returned to the origin of the email.
What can be done to resolve this?

The log message above suggests that the header_checks access file
contains a DISCARD entry which matches that "From" header.