SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that allows you to send out e-mail messages from your email addresses. Without it, you won't be able to employ e-mail apps or webmail. Once you send a message, your SMTP server creates a connection to a DNS server to discover exactly where e-mails for the recipient domain are managed. Following that, it connects to the remote email server and exchanges details. If the recipient mail box is present, your server transmits the email to the receiving POP/IMAP server and the latter brings that e-mail to the specific mailbox in which the receiver can find it. If you want to send e-mails, it is recommended to make certain that the website hosting company offers the service with their packages. Even if you use an online form that visitors use to get hold of you, you still require an active SMTP server for your hosting account for the web form to function.