When creating a user or changing mail settings in Plesk, the following error is encountered:
There is no mail service for domain with id = 1. It must be created before call update
Error: There is no DSMail service for domain with id = 1
The Mail service entry is missing for a domain in the psa database for one of the subscriptions.
Run Plesk autoinstaller and make make sure that all components were installed.
Try to activate the Mail service for the domain via CLI
# /usr/local/psa/bin/domain --update example.com -mail_service true
"%plesk_bin%\\mail.exe" --update-service example.com -status enabled