In order for you to send out emails through an e-mail address with your own domain, you have to make sure that the provider will provide you with access to their SMTP server. The latter is the software allowing email messages to be sent out. SMTP is an abbreviation for Simple Mail Transfer Protocol and it handles all outgoing email messages from apps, webmail and contact web forms. When a message is sent out, the SMTP server checks with all of the DNS servers globally where the e-mails for the receiving domain are managed and when it gets this info, it connects to the remote POP/IMAP server to check if the recipient mail box is available. In case it does, the SMTP server transmits the email body and so the receiving server sends it to the mailbox where the recipient can open it up and see it. Without an SMTP server on your server, you will not be capable to mail out e-mails in any way.