SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that permits you to send out messages from your email addresses. Without this, you will not be able to employ e-mail applications or webmail. Whenever you send an email, your SMTP server creates a connection to a DNS server to determine where the e-mails for the recipient domain name are managed. Subsequently, it connects to the remote email server and trades details. In case the recipient mailbox is accessible, your server sends the message to the receiving POP/IMAP server and the latter brings that e-mail to the precise mailbox in which the recipient can get it. If you want to be able to send e-mails, it is recommended to make certain that the web hosting company offers the service with their plans. Even if you make use of online form that site visitors use to make contact with you, you will still need an active SMTP server for your hosting account for the web form to work.