SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that allows you to send e-mails from your email addresses. Without this, you won't be able to employ e-mail apps or webmail. When you send an email, your SMTP server creates a connection to a DNS server to discover where the e-mails for the recipient domain name are taken care of. Subsequently, it creates a connection to the remote mail server and exchanges details. If the recipient mail box exists, your server transmits the email to the receiving POP/IMAP server and the latter brings that message to the precise mailbox in which the recipient can see it. If you'd like to be able to send e-mails, it is best to make sure that the website hosting company has the service with their plans. Even though you use 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 form to operate.