If you'd like to send out email messages using an email address with your domain, you have to make sure that the company will give you access to their SMTP server. The aforementioned is the software allowing email messages to be dispatched. SMTP is an acronym for Simple Mail Transfer Protocol and it handles all outgoing e-mails from applications, webmail and contact web forms. Whenever a message is sent, the SMTP server confirms with all the DNS servers worldwide where the e-mails for the receiving domain are managed and when it acquires this info, it connects to the remote POP/IMAP server to see if the recipient mail box is out there. If it does, the SMTP server directs the email body and so the receiving server sends it to the mail box where the recipient can open it and read it. Without an SMTP server on your end, you will not be allowed to send out messages in any way.