SMTP, which stands for Simple Mail Transfer Protocol, is the software that allows you to send e-mail messages from your email addresses. Without it, you won't be able to use e-mail applications or webmail. Whenever you send a message, your SMTP server connects to a DNS server to determine where the e-mails for the recipient domain name are taken care of. Following that, it connects to the remote mail server and exchanges information. In case the recipient mail box is available, your server sends the email to the receiving POP/IMAP server and the latter delivers that email to the precise mailbox where the recipient can access it. If you'd like to send emails, it is recommended to ensure that the hosting company provides the service with their packages. Even though you use an online form that visitors use to get hold of you, you will still require an active SMTP server for your hosting account for the form to operate.