If you would like to send out email messages using an email address with your own domain, make sure that the company will provide you with access to their SMTP server. The latter is the software which enables email messages to be sent. SMTP is an abbreviation for Simple Mail Transfer Protocol and it handles all outgoing emails from apps, webmail and contact forms. When a message is sent, the SMTP server confirms with all of the DNS servers globally where the e-mails for the receiving domain are managed and once it gets this info, it will connect into the remote POP/IMAP server to check if the recipient mail box is available. When it does, the SMTP server sends the message body and so the receiving server delivers it to the mailbox in which the recipient can open it up and see it. With no SMTP server on your end, you will not be capable to send out e-mails in any way.