SMTP, which stands for Simple Mail Transfer Protocol, is the software that permits you to send messages from your email addresses. Without it, you will not be able to use email applications or webmail. Once you send a message, your SMTP server connects to a DNS server to discover exactly where emails for the recipient domain name are managed. Subsequently, it creates a connection to the remote mail server and trades information. In case the recipient mailbox exists, your server sends the message to the receiving POP/IMAP server and the latter brings that e-mail to the precise mailbox where the receiver can access it. If you'd like to be able to send emails, you should always make certain that the website hosting company offers the service with their plans. Even though you use an online form that visitors use to get hold of you, you'll still require an active SMTP server for your hosting account for the web form to work.