SMTP, which is short for Simple Mail Transfer Protocol, is the software that allows you to send messages from your email addresses. Without this, you won't be able to employ e-mail applications or webmail. Whenever you send an e-mail, your SMTP server connects to a DNS server to find out exactly where e-mails for the recipient domain are taken care of. Following that, it connects to the remote mail server and trades information. When the recipient mail box exists, your server transmits the e-mail to the receiving POP/IMAP server and the latter delivers that email to the particular mailbox where the recipient can get it. If you would like to be able to send emails, it is best to ensure that the web hosting company offers the service with their packages. 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 function.