SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that permits you to send emails from your email addresses. Without this, you won't be able to use e-mail applications or webmail. Once you send an e-mail, your SMTP server creates a connection to a DNS server to find out where the e-mails for the recipient domain name are managed. After that, it creates a connection to the remote mail server and trades details. In case the recipient mailbox exists, your server transmits the message to the receiving POP/IMAP server and the latter delivers that e-mail to the particular mailbox in which the recipient can get it. If you'd like to be able to send emails, it is recommended to make sure that the hosting company offers the service with their packages. Even when you make use of online form that website visitors use to get hold of you, you'll still require an active SMTP server for your hosting account for the web form to work.