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Home » GFI User Forums » Kerio Connect » Sent emails are blocked as SPAM to some recepients
Sent emails are blocked as SPAM to some recepients [message #150322] Wed, 29 September 2021 18:45 Go to next message
SMV is currently offline  SMV
Messages: 1
Registered: September 2021

We have just set up an Kerio Connect email server to replace our Mac OSX server's emailserver.
After running a few days we are blocked from some customers email servers
and emails are rejected. Only a couple of percent are blocking us as SPAM.
We have been sending mails for many years to these addresses and never been blocked as spam,
so something has changed.
In history we encountered some problem that our server was not identifying itself to our
ipadress and or dns name in the sending procedure. It pointed to localhost and not our domain or IP or something I forgotten.
However I remember fixing something on OSX unix mail servers in a file with the Terminal and the problem went away
that time.

Can this be some kind of similar problem?
This line in the header of the response bothers me:
"Received: from localhost ([])"

Anyone have any tip?

Best Regards
Magnus Torell

We get responses like below: (from Kerio I suppose)

<valid<_at_>customer.domain> ( 550 5.7.1 [SPAM])Reporting-MTA: dns;
Arrival-Date: Wed, 29 Sep 2021 13:19:33 +0200

Original-Recipient: valid<_at_>customer.domain
Final-Recipient: rfc822;valid<_at_>customer.domain
Action: failed
Status: 5.3.2
Diagnostic-Code: SMTP; 550 5.7.1 [SPAM]
Message-ID: <826802303-347131904<_at_>>
X-Footer: c212LnNl
Received: from localhost ([])
by (Kerio Connect 9.3.1 patch 1) with ESMTPSA
(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits))
for valid<_at_>customer.domain;
Wed, 29 Sep 2021 13:19:33 +0200

Re: Sent emails are blocked as SPAM to some recepients [message #150330 is a reply to message #150322] Fri, 01 October 2021 17:24 Go to previous message
freakinvibe is currently offline  freakinvibe
Messages: 588
Registered: April 2004
If you go to Configuration > Domains

What does it display as "Internet Hostname" on top? This should match the reverse DNS lookup of the IP address your are sending from. It should not be "localhost" or your internal server name.

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