SMTP stands for “Simple Mail Transfer Protocol”.
Created in 1982, SMTP is an email transfer protocol used for sending Emails.
Although old, this protocol is still used today in the world of emailing, and is standardized by RFC821, RFC2821 and RFC5321.
This protocol, which uses a TCP communication mode, enables an email message to be sent through a connection between an email server (MTA) and another email server, on network port 25. Communication can be either unencrypted or encrypted (using SSL or STARTTLS).
As its name suggests, the SMTP protocol was initially created to ensure simple email transfer, which is why it didn’t natively benefit from the protections needed to cope with the hacking and phishing attempts that are so common these days. It was therefore necessary to supplement this protocol with additional security bricks to cope with today’s threats.
For example, trusted additional protocols have been added in order to certify the sender address ownership, including SPF, DKIM and DMARC, which are widely used in email marketingEmail marketing, also known as Emailing, is a digital marketing strategy that uses email as its medium. It is one of the... More.
Because of security challenges and increasingly complex existing threats, the emailing industry is now considering what additional building blocks has yet to be developed around SMTP, while other email players believe that SMTP is too old, and that the protocol should either be completely rewritten, or a successor found in the years to come.
In addition, email verifierAn email verifier, also known as an email checker, is a software used to check an email address or a list of email addre... More use SMTP protocol commands to perform a key step in order to find the email addressEmail addresses, also known as "electronic addresses" or simply "emails", represent a form of digital communication popu... More status.