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 it, you will not be able to employ email applications or webmail. When you send a message, your SMTP server connects to a DNS server to learn where the emails for the recipient domain name are handled. Following that, it connects to the remote email server and trades details. In case the recipient mailbox is present, your server sends the e-mail to the receiving POP/IMAP server and the latter brings that e-mail to the specific mailbox in which the recipient can access it. If you would like to send emails, you should always make certain that the website hosting company offers the service with their packages. Even though you use an online form that website visitors use to contact you, you will still need an active SMTP server for your hosting account for the form to operate.