How do I completely stop the [system] / mailnull as the sender sending out emails?
When I run the following using the Message ID for new emails nothing is showing up but it's showing as Frozen under Mail Queue Manager:
exigrep "1k3mNa-0000fO-DT" /var/log/exim_mainlog
What's happening is the [system] is receiving non-stop emails for non-existent accounts on the server and when failed the [system] is sending the failed email messages to many Recipients email addresses as from/reply-to addresses set by the spammers.
For example:
Code:
Received: from mailnull by hostname.com with local (Exim 4.93)
id 1k4soL-0005kD-DK
for [email protected]; Sun, 09 Aug 2020 17:24:57 -0400
Subject: Mail delivery failed: returning message to sender
[email protected] doesn't exist on the server, not sure why mailnull is even accepting the emails for accounts not hosted on the server and then replying as failed?
or if it's locally being generated by the [system], how do I find the source?
Also it says received from esmtpsa for some of the emails:
Code:
Received: from [188.187.18x.24x] (port=60554 helo=hxgr)
by hostname.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
(Exim 4.93)
(envelope-from <[email protected]>)
id 1k1Qaf-0001sX-Rs; Fri, 31 Jul 2020 04:40:34 -0400
But the envelope-from address is not hosted on the server.
Thank you!