When an email client or outgoing server is submitting an email to be routed by a proper mail server, it should always use SMTP port 587 as the default port. This port, coupled with TLS

IMAP is better if you are going to be accessing your email from multiple devices, such as a work computer and a smart phone. POP3 works better if you are only using one device, but

The ports typically used for POP are TCP ports 110 and 995, and for IMAP are TCP ports 143 and 993, for insecure and secure sessions respectively. De plus, Is port 587 a SSL? msa