|^^|
To disable an e-mail account from the server, kindly run this command.
usermod -L -e 1 [ USERNAME ]
Just change the [ USERNAME ] with the account that you wished to lock. The '-L' parameter was used to lock the account. The '-e 1' was used to set the expiration date of the account.
To unlock an account, you can use this command.
usermod -U -e "" [ USERNAME ]
The '-U' parameter was used to unlock the account. The '-e ""' parameter was used to disable the account expiration date.
eof