Problem with Email settings

Hi ,
Ihave problem with Email settings. My account has smtp_auth = STARTTLS.
byt when I type the mail… is not sent. My configuration is below.

Use SMTP for sending mail instead of mail()
smtp = On

; SMTP server settings
smtp_server = moskit.uwm.edu.pl
smtp_port = 587

; Enable SMTP authentication
; Supported mechanisms: ssl, tls
smtp_auth = STARTTLS
smtp_username = ***********
smtp_password = **********