SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that allows you to send out e-mails from your email addresses. Without this, you won't be able to employ e-mail applications or webmail. When you send an email, your SMTP server creates a connection to a DNS server to learn exactly where emails for the recipient domain name are taken care of. Following that, it creates a connection to the remote email server and trades details. When the recipient mail box is available, your server sends the message to the receiving POP/IMAP server and the latter delivers that e-mail to the particular mailbox where the receiver can see it. If you would like to send emails, it is recommended to make certain that the web hosting company provides the service with their plans. Even when you use an online form that website visitors use to contact you, you will still need an active SMTP server for your hosting account for the form to operate.