Rename a user / change username
From Andreida
Avoid to change the passwd directly. There might be problems in some cases.
Instead use:
usermod -l newname oldname
Rules:
- only lowercase
- only use '-' as special character, but avoid it if you can
In case the user is using imap to access the mail server you will have to shut down the service temporarily I think.
/etc/init.d/dovecot stop usermod -l newname oldname /etc/init.d/dovecot start
(not sure yet if a reboot helps prevent problems)