SMTP, which stands for Simple Mail Transfer Protocol, is the software that allows you to send e-mail messages from your email addresses. Without it, you won't be able to employ email apps or webmail. After you send a message, your SMTP server connects to a DNS server to discover exactly where emails for the recipient domain are handled. Subsequently, it creates a connection to the remote mail server and exchanges details. When the recipient mail box is present, your server transmits the message to the receiving POP/IMAP server and the latter delivers that email to the specific mailbox in which the receiver can access it. If you wish to be able to send emails, you should always ensure that the hosting company offers the service with their plans. Even though you work with an online form that website visitors use to make contact with you, you will still need an active SMTP server for your hosting account for the form to function.