– You might be getting alerts from chkservd claiming that your
IMAP/exim is getting failed and is being restarted automatically
by chkservd.

Although you might not be experiencing any real time
issue with mail delivery or logging in, something would be wrong
and as a result, you are getting this alert.

– Check /var/log/chkservd.log and see if something similar to the
following is present :

> AUTH PLAIN xxxxxxxxxxxxxxxxxxxxxx

<< 421 host.xxxx.com Service not available - closing connection
exim: ** [421 host.xxxx.com: Service not available - closing connection != 2]

– This indicates that the check daemon is not able to authenticate
with the temporal exim-auth-key and therefore negative result is obtained which is forcing chkservd to restart the services in a hope
for fixing it.

– To fix this, regenerate the keys

# cd /var/cpanel/serviceauth/
# rm -rf exim
# service cpanel restart
# service exim restart

This should correct the issue.