* It allows you to send/receive mail from your [[Intro|HDA]]. There are some quirks depending on if you have a registered domain with a paid service provider (i.e. [http://www.godaddy.com GoDaddy], [http://www.hostgator.com Host Gator], etc). With these services, there is typically what is called a MX record associated with the domain name. This will allow you to send/receive mail as your hostname (i.e. myhda@home.com).

* If you use the free ones (i.e. user.yourhda.com, [http://www.no-ip.org no-ip.org], etc), you will have to [[Masquerade_email_address|masquerade your email address]] as your ISP (i.e. myhda@yourisp.com). This will ensure you can receive email replies from those you send from your [[Intro|HDA]].