Your problem
My problem is: My Mautic site URL is m.mysite.com, but when I send an email that includes a link, all the links are being replaced with tracking.mysite.com/tracking/click?d=…, and none of these links work.
If you are using Google, it can sometimes cause a conflict with tracking links. Try disabling it. Have you also tested this issue with different email providers to see if it happens specifically with one provider or if it’s occurring with various providers?
Additionally, try the email preview to ensure that the links are working correctly.