Hello,
What is the exact error message and what exactly have you tried?
Next, which of the following is this impacting:
- One email account on one domain on a cPanel account
- All email accounts on one cPanel account
- All email accounts on all cPanel accounts
Knowing which is impacted helps to narrow down substantially where the issue is occurring. Here is a breakdown of how providing specific details would be necessary:
[Impacted - one email account on one domain on a cPanel account]
Could be caused by incorrect permissions (ownership or file) on /home/username/mail/domain.com/passwd, shadow or quota file permissions
Could be caused by missing user /home/username/mail/domain.com/passwd, shadow or quota file(s)
Could be caused by incorrect permissions (ownership or file) on /home/username/mail/domain.com/emailuser folder or subfolder (cur, new)
Could be caused by missing /home/username/mail/domain.com/emailuser folder or subfolder (cur, new)
And so on
[Impacted - all email accounts on one cPanel account]
Could be caused by incorrect permissions (ownership or file) on any level leading up to /home/username/mail/domain.com/passwd, shadow or quota file(s)
Could be caused by missing users in /home/username/mail/domain.com/passwd, shadow or quota file(s)
Could be caused by setting immutable attributes on /home/username/mail/domain.com/passwd, shadow or quota file(s)
Could be caused by incorrect permissions (ownership or file) on any folders leading up to /home/username/mail/domain.com
Could be caused by missing /home/username/mail or /home/username/mail/domain.com folders
Could be caused by domain not being properly owned (/scripts/whoowns domain.com)
Could be caused by account not having been properly unsuspended (grep -i suspend /var/cpanel/users/username)
Could be caused by domain not digging to the machine for the DNS zone
Could be caused by the domain not being in /etc/localdomains and/or in /etc/remotedomains
And so on
[Impacted - one email account on one domain on a cPanel account]
Could be caused by exim not running
Could be caused by CSF firewall or iptables blocking port incoming and/or outgoing 25
Could be caused by immutable attribute set on /etc/exim.conf or any exim file(s) needing to be updated
Could be caused by Perl module issues
Could be caused by domains being in /etc/remotedomains
Could be caused by resolver not working (/etc/resolv.conf)
Could be caused by bind not properly working for named resolving local domains
And so on
There are many reasons that email might not function because email is extremely complex. At all points in time when reporting an error message, please ensure to provide whether it is just one email account on a domain, all email accounts on a cPanel account, or all email accounts on the machine. If you are unable to provide additional information for privacy concerns, then please submit a ticket using WHM > Support Center > Contact cPanel or using the link in my signature. If you post the ticket number upon opening one, we can track the progress of the ticket.
Please note that if you do not have root SSH and root WHM access, you would want to contact your datacenter, NOC or provider to have them investigate the issue. If they are unable to resolve it, then they could submit a ticket to us using our support channels.
Thanks!