To stop forwarding DMACC emails to your personal email please do the following steps...
Sign in to myDMACC, then click Webmail on the left side of the page.
You can also sign in directly to Webmail here.
Click on the Settings icon at the top-right of the page.
In the search field, type in Forwarding.
Click on Forwarding when it appears.
Uncheck Enable Forwarding
Once that's configured to your liking, just be sure to click Save at the top-right of that window.
Now your DMACC email will stop being forwarded to your personal email.