Reliable SMTP service provider for hassle-free marketing and transactional emails without managing your own mail server.| Mailgun
Port 25 is for SMTP relays, 587 for mail submission, and 465 for implicit TLS. Discover the use cases for each SMTP port in this guide.| Mailgun
This document is a specification of the basic protocol for Internet electronic mail transport. It consolidates, updates, and clarifies several previous documents, making all or parts of most of them obsolete. It covers the SMTP extension mechanisms and best practices for the contemporary Internet, but does not provide details about particular extensions. Although SMTP was designed as a mail transport and delivery protocol, this specification also contains information that is important to its ...| IETF Datatracker