It's a mild inconvenience to you, to some number of your customers, it will mean they never follow-up on whatever presumably important message you were sending

It's a mild inconvenience to you, to some number of your customers, it will mean they never follow-up on whatever presumably important message you were sending them. Keep telling people not to click on links, ever. The ones who listen, and are paranoid about taking that advice literally, will look the company up on a search, or copy-and-paste the link instead of clicking it. If I get a link from a company I have an account with, and the link is from their URL, I'm going to click it. I'll also check to make sure there wasn't some kind of redirect or Punycode involved. But you're not helping your customers by refusing to provide them with an important affordance just because scammers might do something similar. That kind of logic doesn't help anyone, because "anyone" breaks down into two groups: the ones who click, and the ones who don't. The ones who click get to resolve the problem, the ones who don't have to do a search first, exactly what you're suggesting forcing everyone to do.