If you want to send e-mail messages through an e-mail address with your personal domain name, you have to make sure that the provider will provide you with usage of their SMTP server. The aforementioned is the software system allowing e-mails to be sent out. SMTP is an abbreviation for Simple Mail Transfer Protocol and it manages all outgoing email messages from apps, webmail and contact forms. When a message is sent out, the SMTP server checks with all the DNS servers around the world where the emails for the receiving domain name are managed and as soon as it acquires this info, it will connect into the remote POP/IMAP server to see if the recipient mail box is out there. If it does, the SMTP server delivers the message body and then the receiving server sends it to the mail box in which the recipient can open it up and see it. Without an SMTP server on your end, you won't be allowed to send out e-mails at all.