When you have a shared hosting package and you create an email address, you might take the option to send out and receive emails for granted, but in fact, that isn't always true. Sending email messages is not always part of the web hosting plans that companies feature and an SMTP service is required to be capable to do that. The acronym stands for Simple Mail Transfer Protocol and that is the piece of software that enables you to send e-mails. If you are using an e-mail application, it creates a connection to the SMTP server. The latter then looks up the DNS records of the domain, that is a part of the receiving address to find out what email server deals with its e-mails. After system information is swapped, your SMTP server delivers 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 necessary if you work with some sort of contact form too, so in case you work with a free of charge hosting plan, for example, it is likely that you will not be able to use such a form as most free web hosting companies do not allow outgoing email messages.