A: Hi,

It's Alex, the founder of ProxiedMail.
Thank you for reaching out to me.

We have a soft limit, but we don't support brining your own key.
Basically I would say that even if you have a 1K messages with AI bot - it won't be the issue.
In case it would be a lot of people like that we might implement bringing your own key.

But for sure, I don't see anyone now who's exceeding the limit.