In case you have a shared hosting package and you set up an e-mail address, you may take the option to send out and receive emails for granted, but in fact, this isn't always true. Sending email messages is not always included in the website hosting plans that companies will offer you and an SMTP service is required to be able to do that. The acronym means Simple Mail Transfer Protocol and that is the set of scripts that enables you to send e-mail messages. If you use an e-mail application, 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 which mail server manages its e-mails. After some system data is swapped, your SMTP server delivers the message to the remote IMAP or POP server and the e-mail is finally delivered in the related mailbox. An SMTP server is necessary if you use some sort of contact page too, so in case you work with a cost-free hosting plan, as an example, it's probable that you will not be able to use such a form as many no charge web hosting service providers do not allow outgoing email messages.