When you have a hosting plan and you create an email address, you may take the option to send out and receive emails for granted, however, that isn't always the case. Sending emails is not always a part of the hosting plans that providers have and an SMTP service is required to be capable to do that. The acronym represents Simple Mail Transfer Protocol and that is the piece of software that enables you to send out e-mails. If you are using an e-mail program, it connects to the SMTP server. The latter then requests the DNS data of the domain name, which is a part of the receiving address to find out which email server handles its emails. After some system information is exchanged, your SMTP server provides the message to the remote IMAP or POP server and then the e-mail is finally delivered in the related mailbox. An SMTP server is required if you use some kind of contact form also, so in case you have a free hosting package, for example, it is very likely that you will not have the ability to make use of such a form as most free website hosting providers do not allow outgoing email messages.