Forwarders

Email forwarders such as you@yoursite.com can forward email to another address like yourname123@gmail.com.  These can be created like so:
   

Testing your forwarder


After you have set-up a forwarder, for example:
you@yoursite.com to yourname123@gmail.com
send yourself an email to you@yoursite.com from an different account than yourname123@gmail.com.
 

Sending from you@yoursite.com


Google Workspace
The easiest way is to send email from a you@yoursite.com address would be to use a dedicated email hosting service such as Google Workspace.

Creating a custom address within Gmail
Some Gmail accounts may allow to to set-up an additional custom addresses within the account.
 
Why is my forwarder not working?
Some email service providers (for example, comcast.net) will periodically filter your messages away from the inbox, or not deliver them at all.  This is usually due to overly agressive spam filtering.  For best results, forward to a Gmail account.