Give the full name of one or more local SMTP servers that Moodle should use to send mail (eg 'mail.a.com' or 'mail.a.com;mail.b.com'). To specify a non-default port (i.e other than port 25), you can use the [server]:[port] syntax (eg 'mail.a.com:587'). For secure connections, port 465 is usually used with SSL, port 587 is usually used with TLS, specify security protocol below if required. If you leave this field blank, Moodle will use the PHP default method of sending mail.