Re: SMTP relay issue with emails to specific domain
Hi Daniel,
Daniel Bareiro:
>
> On 08/09/16 13:56, Daniel Bareiro wrote:
>
>> I recently set up an relay SMTP server on a host of Digital Ocean, using
>> Debian and Postfix.
>>
>> The main reason for setting up this relay is that the cPanel VPS is
>> hosted at Godaddy, and they force everyone to send email through their
>> shared SMTP relay. As expected, that shared relay is continually being
>> flagged for spam.
>>
>> So the outgoing emails are routed through this server. Usually
>> everything worked smoothly. Mails to accounts on Google, Yahoo, Hotmail
>> and other servers are delivered. But I found a problem with a specific
>> domain:
>>
>> -----------------------------------------------------------------------
>> Sep 7 14:36:11 smtp postfix/smtp[8036]: 5EAA520AAD:
>> to=<xxxx@lkeusa.com>, relay=lkeusa.com[50.87.144.56]:25], delay=13,
>> delays=0.91/0.06/6.1/5.9, dsn=5.0.0, status=bounced (host
>> lkeusa.com[50.87.144.56] said: 550-Please turn on SMTP Authentication in
>> your mail client, or login to the 550-IMAP/POP3 server before sending
>> your message. smtp.server.com 550-[x.y.z.t]:41988 is not permitted to
>> relay through this server 550 without authentication. (in reply to RCPT
>> TO command))
>> -----------------------------------------------------------------------
>>
>> I'm not sure why this specific domain is complaining in this way.
I think it's because it requires SMTP authentication, whereas apparently
the other servers you mention don't (mails are delivered). Have you
checked if the mail client's option mail.smtpserver.default.authMethod
is set to 0, which means there is no SMTP authentication at all. That
could explain the issue.
For a list of methods, see (1)
Looking at exim's server ready 220 response below, it does not like
people to send spam or bulk email.
The 550 return code means that the mailbox you are trying to reach can't
be found or you are lacking access rights. In your case it's the latter,
as the server response indicates.
(1) http://www.afterlogic.com/mailbee/docs/SMTP_props_AuthMethod.htm
Stephan
[...]
>
> Well, it seems that in the absence of an MX record, Postfix uses the A
> record that it find by querying that domain and in that IP address an
> Exim server responds:
>
> -----------------------------------------------------------------------
> # telnet lkeusa.com 25
> Trying 50.87.144.56...
> Connected to lkeusa.com.
> Escape character is '^]'.
> 220-gator3037.hostgator.com ESMTP Exim 4.86_1 #1 Thu, 08 Sep 2016
> 12:15:19 -0500
> 220-We do not authorize the use of this system to transport unsolicited,
> 220 and/or bulk e-mail.
> -----------------------------------------------------------------------
>
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