This user cpanel account reached disk quota limit and mail stopped working. User deleted about 4G of emails and released some disk space. Problem was that he still wasn’t able to login to webmail. This error was shown:
internal server error 500 user is over quota cpanel
It didn’t make sense since he released his disk space. Cpanels quota was showing new value, but login to webmail was still impossible.
What you have to do is remove cpanels overquota file manually. Let’s say that user user4 is having issue described above.
root@cpanel [~]# cd /var/cpanel/overquota/ root@cpanel [/var/cpanel/overquota]# ls ./ ../ user1 user2 user3 user4 root@cpanel [/var/cpanel/overquota]# rm user4
After I deleted /var/cpanel/overquota/user4, webmail was started to working again.