SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that enables you to send out emails from your email addresses. Without this, you will not be able to employ e-mail applications or webmail. After you send an email, your SMTP server creates a connection to a DNS server to discover exactly where emails for the recipient domain name are managed. Then, it connects to the remote email server and trades information. When the recipient mailbox is present, your server sends 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 e-mails, it is recommended to ensure that the hosting company provides the service with their plans. Even when you work with an online form that visitors use to get hold of you, you'll still need an active SMTP server for your hosting account for the web form to operate.