SMTP, which is short for Simple Mail Transfer Protocol, is the software that allows you to send emails from your email addresses. Without it, you will not be able to employ email apps or webmail. After you send a message, your SMTP server connects to a DNS server to find out where the emails for the recipient domain name are managed. Then, it connects to the remote mail server and trades details. When the recipient mailbox is present, your server transmits the e-mail to the receiving POP/IMAP server and the latter delivers that e-mail to the precise mailbox where the receiver can find it. If you'd like to send emails, it is recommended to make certain that the web hosting company has the service with their plans. Even when you use an online form that visitors use to get hold of you, you still require an active SMTP server for your hosting account for the web form to operate.