Forums Feature Suggestions A switch to disable SendMessage processing

His remark was sure relevant, it's rather what you are saying that is irrelevant.
The request is ok, DDE can be disabled, perhaps sendmessage() could/should too, just for consistency, now arguing that you want it because of a security issue is a bit irrelevant, as pointed out, if you are concerned with external programs interacting with mIRC in a bad way because of sendmessage(), you should be already concerned with what the externals programs can currently do (see loki's list). And if you trust the program you are using for now about not enabling DDE to use it maliciously, you also trust them for sendmessage, so the security risk is quite irrelevant imo, though present.

edit: Sendkey is not a part of mIRC just like regular expressions, so they are not documented in the help file, as expected.