SMTP, which stands for Simple Mail Transfer Protocol, is the software that enables you to send out e-mail messages from your email addresses. Without it, you won't be able to employ email apps or webmail. When you send an e-mail, your SMTP server creates a connection to a DNS server to learn where the e-mails for the recipient domain are managed. Following that, it connects to the remote email server and trades information. In case the recipient mail box exists, your server sends the message to the receiving POP/IMAP server and the latter brings that email to the precise mailbox where the receiver can get it. If you would like to be able to send emails, it is best to make certain that the hosting company provides the service with their plans. Even if you use an online form that site visitors use to get hold of you, you will still require an active SMTP server for your hosting account for the web form to operate.