Convalidate email before confirm the saving

[PeopleInside]

When you add email in Swift mailer or on email box do the check if password and IMAP settings are correct. If password is not accepted or IMAP, server, etc config is not correct give an error.

Actually the system save all as OK even email info and credentials are not valid. No error so operator, admin think all is good when is not.

Add also a button save and test for send a test email. There is no sending test tool inside the operator panel and, on email configuration, is important to test everything works.