SMTP, which is short for Simple Mail Transfer Protocol, is the software that enables you to send out emails from your email addresses. Without this, you will not be able to employ email apps or webmail. After you send an email, your SMTP server connects to a DNS server to determine exactly where e-mails for the recipient domain name are taken care of. After that, it connects to the remote mail server and trades information. If the recipient mail box is available, your server transmits the e-mail to the receiving POP/IMAP server and the latter brings that email to the specific mailbox in which the receiver can find it. If you wish to be able to send emails, you should always make certain that the hosting company offers the service with their plans. Even though you make use of online form that site visitors use to contact you, you still need an active SMTP server for your hosting account for the form to operate.