SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that enables you to send out messages from your email addresses. Without this, you will not be able to employ email applications or webmail. Every time you send a message, your SMTP server connects to a DNS server to determine exactly where emails for the recipient domain are taken care of. Following that, it connects to the remote mail server and trades information. If the recipient mail box is accessible, your server transmits the message to the receiving POP/IMAP server and the latter delivers that email to the precise mailbox where the recipient can see it. If you want to send emails, it is best to make sure that the hosting company has the service with their packages. Even though you make use of online form that site visitors use to contact you, you will still need an active SMTP server for your hosting account for the web form to operate.