on a specific domain, we are getting mail delivery failures.
When I inspected the issue, I found this:
-----Original Message-----
From: Delivery Subsystem <POSTMASTER@***.com>
Sent: Thursday, August 12, 2021 12:25 AM
To: umitakyuz@***.com
Subject: Message Delivery Failure - EFT/SWIFT Hesap Ekleme
MailEnable: Message could not be delivered to some recipients.
The following recipient(s) could not be reached:
Recipient: [SMTP:****@takasbank.com.tr]
Reason: Mail server for takasbank.com.tr is not contactable. Message
has expired and has been returned to Sender.
Message contents follow:
Received: from MUHASEBE1 ([78.189.216.***]) by ***.com with
MailEnable ESMTPA; Mon, 9 Aug 2021 15:43:40 +0300
From: =?iso-8859-9?B?3G1pdCBBa3n8eg==?= <umitakyuz@***.com>
To: <***@takasbank.com.tr>
Subject: EFT/SWIFT Hesap Ekleme
Date: Mon, 9 Aug 2021 15:43:37 +0300
Message-ID: <003601d78d1c$2d179580$8746c080$@hakandoviz.com>
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_0037_01D78D35.526569C0"
X-Mailer: Microsoft Outlook 16.0
Thread-Index: AdeNHCf0WU0VYvN4Tqa+S/Awbzr4rQ==
Content-Language: tr
X-ME-Bayesian: 40.000000
This is a multipart message in MIME format.
------=_NextPart_000_0037_01D78D35.526569C0
Content-Type: multipart/related;
boundary="----=_NextPart_001_0038_01D78D35.526569C0"
------=_NextPart_001_0038_01D78D35.526569C0
Content-Type: multipart/alternative;
boundary="----=_NextPart_002_0039_01D78D35.526569C0"
------=_NextPart_002_0039_01D78D35.526569C0
Content-Type: text/plain;
charset="iso-8859-9"
Content-Transfer-Encoding: quoted-printable
As you can see, it says "the remote mail server is not contactable."
I log on to the server and check the connection for the remote mailserver by telnet.
Yes, the port 587 was unreachable but port 25 was running OK on the remote side and the connection succedeed.
Doesn't MailEnable ever use port 25 for outgoing smpt servers? Or is there a configuration area for this that I'm missing?