Staged users and new user’s limitations

I’m not totally sure if I just don’t understand how things works or do I have some settings wrong, but I guess my case is part of quite commom practise.

I use PMs via email and therefor staged users as a support channel. But because those users are new ones they can’t see my PM unless I promote them to TL1 or (I reckon, didn’t test this) after 24 hours introducing/cooling time.

I solved it quite easily by promoting every new user to TL1. I can do that, because I don’t have spam issues, but because I’ve activated e-mail that situation may change. Hopefully not, but I already got spam PM via email.

This is not a real issue, because they can answer using email, but because I give them an invitation link with explanation how they can find that private topic from inbox, it changes to an issue if they actually use invitation and try answer using PM that they can’t see.

So, what the I did again wrong?