You are unable to send and receive email for a domain. When you attempt to enable the mail service, Plesk shows "Mail service on domain is switched off." and the checkbox is disabled / greyed out, preventing you from re-enabling the mail service.
Problem Resolution
When this occurs it means that the overall domain has its hosting disabled. To resolve this problem complete the following steps:
- In Plesk, choose the Website & Domains tab
- Choose Hosting Settings to the right of the domain you need to fix
- Notice the "Website status" option is NOT "Active". Click Change
- Adjust the status to "Active" then press the OK button
