Mails sent to invalid, non existent mail accounts which are undelivered to the recipient & still sit in the mail queue are frozen emails. When an email is sent & undelivered the MTA (Mail Transfer Agent) will try to deliver it a couple of times. If still the email is not delivered, it will be added to your mail queue and will show as frozen. On cPanel linux servers, exim is the MTA configured & the retry limit can be set in exim configuration file under RETRY CONFIGURATION.
If the mail sent isn’t delivered in 8 days, it will be marked as frozen.
Use command below to check the number of frozen emails on the server.
# exim -bp | grep frozen | wc -l
Deleting the emails is a one command job, use the command as below to delete all the frozen emails.
# exim -bp | awk ‘$6~”frozen” { print $3 }’ | xargs exim -Mrm
You can also set a cron job to delete these frozen emails daily OR weekly.
Login to your server as root & create a file /root/frozen.sh. Enter the command above to delete frozen emails in this file. Now, schedule a cron to execute daily OR weekly.
Command below will edit the crontab for user root
# crontab -e
Enter the entry as below to schedule it daily.
0 0 * * * /bin/sh /root/frozen.sh
Once done, use command below to check it is has been set.
# crontab -l
It should show an output as below.
You can follow the steps above on your linux VPS hosting OR linux dedicated servers to manage/delete the frozen emails.
