devi sostituire a localhost un server esterno SMTP valido, ad esempio quello del provider con il quale ti colleghi ad Internet

codice:
[mail function]
; For Win32 only.
SMTP = localhost
smtp_port = 25
sendmail_from = me@localhost.com

; For Win32 only.
;sendmail_from = me@localhost.com

; For Unix only. You may supply arguments as well (default: "sendmail -t -i").
;sendmail_path =