If you have a cloud hosting account and you create an email address, you may take the option to send out and receive messages for granted, however, this isn't always true. Sending e-mails isn't necessarily a part of the web hosting packages that service providers feature and an SMTP service is required to be able to do that. The abbreviation signifies Simple Mail Transfer Protocol and that is the piece of software that allows you to send out e-mails. If you use an e-mail program, it connects to the SMTP server. The latter then looks up the DNS data of the domain name, that is a part of the receiving address to find out which email server deals with its e-mails. After system information is swapped, your SMTP server provides the message to the remote IMAP or POP server and then the e-mail is finally delivered in the corresponding mailbox. An SMTP server is necessary if you are using some sort of contact form too, so in case you use a free hosting plan, as an example, it is very likely that you won't be able to make use of such a form since many free hosting providers do not allow outgoing email messages.