The typical SMTP server used by WordPress is the host's service. It could be mail.exampledomain.com or mail.hostname.com. The common SMTP port is 465, including encryption. Most of the times, the incoming server settings are used for SMTP or outgoing WordPress email settings. Generally, the PHP mail function is used by WordPress to send mails. SMTP server uses the Ports 25, 465, 587, or 2525 for SMTP, but only 587 or 2525 really should be considered for modern use.