Type Definition new_tokio_smtp::send_mail::MailSendResult

type MailSendResult = Result<(), (usize, LogicError)>;

The result of sending a mail

This is either () meaning it succeeded or a tuple of the index of the command which failed and the error with witch it failed. (Detecting that the server does not support SMTPUTF8 but it being required will fail "one the first command", i.e. index 0).