topic Re: Returned mail: Service unavailable in Archive

Returned mail: Service unavailable

cwhiffin — Thu, 01 Sep 2016 14:15:26 GMT

Hi,

I'm having a sporadic problem sending email using smtp.btconnect.com as a relay.

Occasionally one will be returned by the 'Mail Delivery Subsystem' (MAILER-DAEMON@c2beaomr0[6/7/8/12].btconnect.com), stating permanent delivery errors as the reason. The email addresses being sent to all exist- in most cases these are replies to emails received!

Our email setup is a central Linux server running Dovecot and Postfix, which is set up to allow everyone in the office to log in via Outlook to their own IMAP account. Emails sent from these accounts are forwarded via Postfix to smtp.btconnect.com.

The first occurrence was 25/07/2016, 13:14 and 14:58. Two return receipts.

The second was 31/08/2016, 9:23 to 14:07. Seven returned.

Third time was just now, 01/09/2016, 10:25 and 14:48 - two returned.

Please let me know if you need any more information.

Thanks,

- Craig

Re: Returned mail: Service unavailable

cwhiffin — Fri, 02 Sep 2016 09:21:04 GMT

Hello,

Just found that BT servers are listed as spam:

https://www.spamcop.net/w3m?action=blcheck&ip=213.123.26.184

Re: Returned mail: Service unavailable

cwhiffin — Mon, 12 Sep 2016 07:58:15 GMT

Since this is an ongoing problem, I've tried to use an alternative mail server. I have since found that all BT IP addresses are listed on the PBLs as follows:

https://www.spamhaus.org/pbl/query/PBL231589

Given that the official BT SMTP servers are unusable, why exactly is this policy in place?

Thanks,

- Craig

Re: Returned mail: Service unavailable

cwhiffin — Wed, 02 Nov 2016 15:11:06 GMT

Still happening:

Reporting-MTA: dns; c2beaomr16.btconnect.com
Arrival-Date: Wed, 2 Nov 2016 14:32:55 GMT

Original-Recipient: rfc822;<REMOVED>
Final-Recipient: RFC822; <REMOVED>
Action: failed
Status: 5.0.0
Remote-MTA: DNS; mx3.hotmail.com
Diagnostic-Code: SMTP; 550 SC-001 (COL004-MC6F30) Unfortunately, messages from <ALSO REMOVED> weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors.
Last-Attempt-Date: Wed, 2 Nov 2016 14:32:56 GMT

Re: Returned mail: Service unavailable

cwhiffin — Thu, 03 Nov 2016 08:38:26 GMT

And again:

Reporting-MTA: dns; c2beaomr07.btconnect.com
Arrival-Date: Wed, 2 Nov 2016 14:50:15 GMT

Original-Recipient: rfc822;<REMOVED>
Final-Recipient: RFC822; <REMOVED>
Action: delayed
Status: 4.5.0
Remote-MTA: DNS; mx2.hotmail.com
Diagnostic-Code: SMTP;
Last-Attempt-Date: Wed, 2 Nov 2016 18:56:43 GMT
Will-Retry-Until: Thu, 3 Nov 2016 14:50:15 GMT