You'll see how to create a forwarder in DirectAdmin, so all mail to an address on your domain automatically goes to another address.
Read the article: 2.2 Forwarding mail to Gmail
Videos
Gmail and Outlook in short videos
Short videos without sound, with explanations in speech bubbles.
2
Gmail with your own email address
See how to open the existing SPF record in DirectAdmin with the SPF helper, where to add a service under Include Domain, and how to choose the mode. That way you keep a single SPF record.
Read the article: 2.4 SPF and DKIM when you send via Gmail