When you've got a shared web hosting plan and you create an email address, you might consider the option to send and receive messages for granted, but in fact, that isn't always true. Sending emails isn't always a part of the hosting packages that providers feature and an SMTP service is needed to be capable to do that. The acronym represents Simple Mail Transfer Protocol and that is the set of scripts that enables you to send emails. If you are using an e-mail app, it connects to the SMTP server. The latter then looks up the DNS data of the domain, that is a part of the receiving address to find out what mail server manages its emails. After some system information is interchanged, your SMTP server delivers the email to the remote IMAP or POP server and the e-mail is finally delivered in the corresponding mailbox. An SMTP server is needed if you are using some kind of contact page too, so if you work with a free hosting package, as an example, it is likely that you will not be able to make use of this type of form as many no charge hosting providers don't allow outgoing email messages.