My apologies for misunderstanding. Feature removal requests are sufficiently rare that I thought you were posting a mockup of what you wanted to be able to do, as many others have done. So we definitely agree on that example. I changed the title to be a little clearer that stricter checking is desired.

Unless that example violates a prohibition in the docs, removing this bad feature is still a feature request. The point is moot, however, since RDM is working on a mail module overhaul (for 3.2, I hope) and I doubt previous versions will be separately patched. I will let him decide if examples like this can be sensibly prohibited without disabling something that should be allowed.