SMTP, which is an acronym for Simple Mail Transfer Protocol, is the software that permits you to send out emails from your email addresses. Without this, you won't be able to employ email apps or webmail. After you send an email, your SMTP server connects to a DNS server to determine exactly where e-mails for the recipient domain name are handled. After that, it connects to the remote mail server and exchanges details. When the recipient mail box exists, your server transmits the e-mail to the receiving POP/IMAP server and the latter delivers that e-mail to the particular mailbox in which the receiver can see it. If you would like to be able to send emails, it is recommended to ensure that the web hosting company provides the service with their plans. Even if you make use of online form that site visitors use to contact you, you will still require an active SMTP server for your hosting account for the web form to operate.