Email links won’t open

I cannot open any links from email on any of my Apple devices (iPhone, iPad, MacBook). Whether it’s gmail, iCloud or outlook, when I click on an embedded link I get the same message in all browsers: can’t find server “click.mlsend.com”

Ive tried clearing the case and history, removed pop up blockers, allowed Reader for click.mlsend.com. Don’t know what else to try.