I used to user username.domain when I would log into webmin. or into any mail client. Now I just noticed on one of my domains that it says the username is username@domain. However my other domains are still username.domain.
Is there something that has changed in virtualmin or creating account recently?
It sounds like the username format in System Settings -> Server Templates -> Default -> Mail for Domain was changed. That affects whether it’s user.domain or user@domain.
Unfortunately, it’s not possible to change the format of existing users, though if you change that setting all new users will use the updated setting.