A mail server is a central computer that stores electronic emails for clients over the network. It is much like the post office that obtains emails sent to the user and stores them until it is not requested by a user. It uses standard email protocols to send and receive an email like, simple mail transfer protocol (SMTP) handles outgoing mail requests and sends messages. The POP3 and IMAP protocols are used to process incoming mail and also receive messages. These protocols handle all the connections when users log on to a mail server by using email or webmail interface.
Sometimes, mail servers and web servers are merged in a single machine. However, Hotmail and Gmail (public mail services) and large ISPs (Internet service provides) may use dedicated hardware to send and receive an email. A mail server software must be installed on the computer, which gives permission to the administrator of the system to create and manage email accounts for any domains hosted on the server. For instance, if the domain name ‘javatpoint.com’ is hosted by the server, it has the ability to provide email accounts ending in ‘javatpoint.com.