SMTP is a synonym for Simple Mail Transmission Protocol; in other words, it is an internet standard for sending and receiving electronic mails. It was widely used in the early 1980s and was the complement to UNIX for Unix to Unix Copy Program (UUCP) mail. It was better suited for handling email transfers between machines that were connected physically. It was last updated in 2008 with extended SMTP which is the widely-used protocol of today.
Port 25 is used for the SMTP communication between mail servers; on the other hand, mail client often submits the outgoing emails to a mail server on port 587.Although there are other systems such as Microsoft exchange and IBM notes, webmail systems like Outlook, Gmail and Yahoo mail use their own protocol to access mail box accounts on their mail servers.
SMTP works best when both the sending and receiving machines are connected to the network all the time. SMTP connections are secured by SSL (Secure Sockets Layer) technology.
It is the Simple Way of Communication
SMTP offers the simplest way of communication among various computers in a particular way. Here, one can simply type and send emails to the recipient email address using a simple process from the SMTP server.
Quick and Fast Delivery System
As SMTP servers are working in good condition, one can sent the emails quickly to many recipients at the same time.
Reliable Mode of Communication
SMTP is a reliable mode of communication; if any message is not sent successfully, the server keeps trying to resend it till the transmission becomes successful.
SMTP Can be Maintained Locally
SMTP server is very effective and can be maintained locally and configured to handle very important and sensitive mail messages. Nowadays it is the most widely used standard for sending text-based email messages.