Here is the returned error message
This is the mail system at host mhost.mydomain.com.
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# THIS IS A WARNING ONLY. YOU DO NOT NEED TO RESEND YOUR MESSAGE. #
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Your message could not be delivered for more than 4 hour(s).
It will be retried until it is 5 day(s) old.
For further assistance, please send mail to postmaster.
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The mail system
<
test-hoqse@mail-tester.com>: connect to mail-tester.com[94.23.206.89]:25:
Connection refused
Reporting-MTA: dns; myhost.mydomain.com
X-Postfix-Queue-ID: 43F3291A0023
X-Postfix-Sender: rfc822;
test@subdomain.mydomain.comArrival-Date: Sun, 9 Jun 2019 14:05:19 +0000 (UTC)
Final-Recipient: rfc822;
test-hoqse@mail-tester.comOriginal-Recipient: rfc822;
test-hoqse@mail-tester.comAction: delayed
Status: 4.4.1
Diagnostic-Code: X-Postfix; connect to mail-tester.com[94.23.206.89]:25:
Connection refused
Will-Retry-Until: Fri, 14 Jun 2019 14:05:19 +0000 (UTC)
Return-Path: <
test@subdomain.mydomain.com>
Received: from localhost (localhost [127.0.0.1])
by myhost.mydomain.com (Postfix) with ESMTPA id 43F3291A0023
for <
test-hoqse@mail-tester.com>; Sun, 9 Jun 2019 14:05:19 +0000 (UTC)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple;
d=subdomain.mydomain.com; s=default; t=1560089119;
bh=7NStbqdReQ4CDUjwjUTc/S/AP51Ax5HcGGVWWWt9/kY=;
h=Date:From:To:Subject;
b=HPVzV/wZYEppzbpGrx1m5hXMss2eV5WNp7/P3O8sB0hcRW9yZsoA3f78IlKbldFwO
DbFw1NskGvCPXkzaAVOLjy/LkaoMBs/8oRidEzyAsafQgMr37dhkYgpGQYalW88lAd
8hUNY3TKnQ01MfwwhzJDE2q4I1Mo464IRP2Cwii8=
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
format=flowed
Content-Transfer-Encoding: 7bit
Date: Mon, 10 Jun 2019 00:05:19 +1000
From:
test@subdomain.mydomain.comTo:
test-hoqse@mail-tester.comSubject: Test Mail
Message-ID: <
e572ac6d68186698045bad82afb80737@subdomain.mydomain.com>
X-Sender:
test@subdomain.mydomain.comUser-Agent: Roundcube Webmail/1.3.9
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As shown in message I used roundcube to send this directly from user account, also yes this is being sent from a subdomain email account, but I have setup an account with a normal domain and I am getting same problem.