Inherited from TCustomSmtpCli.Auth
Sends SMTP command AUTH to the mail server to start SMTP authentication according property AuthType.
Note that if property AuthType has been set to smtpAuthAutoSelect the component won't silently fall back to smtpAuthNone if no matching authentication method could be detected, instead method Auth would return with error > 0 in event OnRequestDone.
Using open to handle all in one request
The easiest way to use authentication is to use Open instead of Connect. Open handles the Connect, EHLO and AUTH in one so that you don't need to consider it. This is a typical call to open.
Smtp.Username := 'bob'; Smtp.Password := 'test'; Smtp.authtype := smtpAuthAutoSelect; Smtp.open
In your requestdone event you handle open and trigger the mailfrom-metohd.
if RqType = smtpOpen then begin Smtp.MailFrom; end;
From there you use the ordinary methods you would use without authentication.