If you have a shared website hosting account and you set up an email address, you might take the option to send and receive messages for granted, however, this is not always the case. Sending e-mail messages isn't always part of the website hosting packages that service providers offer and an SMTP service is required to be able to do that. The acronym signifies Simple Mail Transfer Protocol and that is the software application that enables you to send email messages. If you are using an e-mail app, it connects to the SMTP server. The latter then requests the DNS data of the domain, which is a part of the receiving address to find out which email server deals with its email messages. After some system information is swapped, your SMTP server delivers the email to the remote IMAP or POP server and then the email is finally delivered in the matching mailbox. An SMTP server is needed if you work with some kind of contact page form too, so in case you work with a free hosting plan, for instance, it's probable that you will not be able to use this type of form as many free hosting companies don't allow outgoing e-mails.