- Email DIY
Which SMTP Port Should I Use? Understanding Ports 25, 465, & 587
It's a common question that we receive here at Mailgun about SMTP port numbers. To ensure connectivity to our Simple Mail Transfer Protocol (SMTP) endpoint, Mailgun offers multiple SMTP port options, but which one should you use to send email messages? We’ll take a historical look at each SMTP port and then we'll discuss today's methodology for outgoing mail usage.