SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that permits you to send messages from your email addresses. Without this, you will not be able to employ email applications or webmail. Whenever you send a message, your SMTP server creates a connection to a DNS server to find out where the e-mails for the recipient domain name are taken care of. Subsequently, it creates a connection to the remote email server and exchanges information. When the recipient mailbox is available, your server sends the email to the receiving POP/IMAP server and the latter brings that message to the particular mailbox in which the receiver can access it. If you would like to send emails, it is best to make certain that the hosting company offers the service with their packages. Even when you work with an online form that website visitors use to make contact with you, you will still require an active SMTP server for your hosting account for the web form to operate.