SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that permits you to send e-mails from your email addresses. Without this, you will not be able to employ e-mail applications or webmail. Once you send a message, your SMTP server creates a connection to a DNS server to learn exactly where emails for the recipient domain name are managed. Then, it creates a connection to the remote mail server and exchanges details. If the recipient mailbox is accessible, your server sends the email to the receiving POP/IMAP server and the latter delivers that email to the specific mailbox where the recipient can find it. If you want to send e-mails, it is best to make certain that the web hosting company offers the service with their plans. Even when you make use of online form that website visitors use to make contact with you, you'll still require an active SMTP server for your hosting account for the web form to function.