Exim issue most likely due to a corrupt Exim db.
Symptom:
Bounced emails with the message:
“retry time not reached for any host after a long failure period”
Solution:
For cPanel:
cd /var/spool/exim/db rm -f retry retry.lockfile rm -f wait-remote_smtp wait-remote_smtp.lockfile service exim restart
For Linux:
/usr/sbin/exim_tidydb -t 1d /var/spool/exim retry > /dev/null /usr/sbin/exim_tidydb -t 1d /var/spool/exim reject > /dev/null /usr/sbin/exim_tidydb -t 1d /var/spool/exim wait-remote_smtp > /dev/null /scripts/courierup -- force /scripts/eximup --force