SMTP, which stands for Simple Mail Transfer Protocol, is the software that permits you to send e-mails from your email addresses. Without this, you won't be able to employ e-mail apps or webmail. After you send an email, your SMTP server connects to a DNS server to determine where the emails for the recipient domain name are handled. Subsequently, it connects to the remote email server and trades details. If the recipient mail box exists, your server sends the e-mail to the receiving POP/IMAP server and the latter brings that message to the specific mailbox where the receiver can access it. If you would like to send emails, it is recommended to ensure that the website hosting company offers the service with their packages. Even when you use an online form that website visitors use to get hold of you, you'll still need an active SMTP server for your hosting account for the form to operate.