Cpanel autorespond is bouncing messages

I recently had to restore a customer’s server from a full backup. After doing so there have been some issues, and this was one of them. When emails are being received to a certain user the message is bouncing back the the below message.

Cpanel is a hosting platform which allows users to create accounts and manage all aspects of ftp, web, email, and databases. Cpanel provides an easy to use interface for customers as well as administrations to manage the server.

Exim is an open source MTA which is responsible for sending, receiving and routing email on your Cpanel server.

I’m getting the following error:

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

pipe to |/usr/local/cpanel/bin/autorespond user@example.com /home/example/.autorespond
generated by user@example.com

The following text was generated during the delivery attempt:

------ pipe to |/usr/local/cpanel/bin/autorespond user@example.com /home/example/.autorespond
generated by user@example.com ------

sendmail: Not running with correct effective GID. Is sendmail binary setgid mailtrap?
sendmail: Not running with correct effective GID. Is sendmail binary setgid mailtrap?
Reporting-MTA: dns; cpanel.example.com

Action: failed
Final-Recipient: rfc822;|/usr/local/cpanel/bin/autorespond user@example.com /home/example/.autorespond
Status: 5.0.0

I verified that the autoresponder message file is on the server, and permissions look to be correct.

[root@cpanel example]# ls -la /home/example/.autorespond/user@example.com
-rw-r--r-- 1 example example 367 Sep 20 14:40 /home/example/.autorespond/user@example.com
[root@cpanel example]# cat /home/example/.autorespond/user@example.com
From: "Customer Name" <user@example.com>
Content-type: text/plain; charset=utf-8
Subject: Out Of Office

Hi
I will be Out of the Office.

Have a Great Day!

Then checking the exim log files, it shows that it’s attempting to deliver the message, it even delivers it to the users inbox, just bounces back with an error message.

Then attempted to run /usr/sbin/sendmail to see what would happen manually, and I got the same error message about setgid.

I then checked the permissions on this server and compared to another server

Bad server:

-rwxr-sr-x 1 root 498 12039 May 11 07:49 /usr/sbin/sendmail

Good server:

-rwxr-sr-x 1 root mailtrap 12039 May 11 07:49 /usr/sbin/sendmail*

So after seeing the group was wrong, I’m assuming again this is because we restored all the configurations on the server from a. backup.  I sent in the /etc/groups file and update the mailtrap group to be 498.

After fixing group this users issues started to work.