RMT - Can we get some ways to prevent invitations of bots advertis in Novice Network?

[Shut]

I don't know how it is on other servers, but here on Lich, someone amongst the mentor is involved in RMT activity and keep inviting bots in Novice Networks. Those bots just have to accept the invitation, advertise in the chat, then leave before we have the chance to kick them (that way, they can't get penalty for that). [EDIT] We already experienced bots that have been invited several times in Novice Chat.

To cut the root of this, there can be several ways:
1st is controversial: we need to be able to tell which mentor keep inviting bot on the Novice Chat, with eventually a search function. We already have something similar for people we met in instance.
Problem of this, is that it can lead to false accusations on someone that has just invited the bot without knowing it.

Another system would be to have some kind of blacklist for RMT, which lead automatically to a report. But that has inconvenient if it just become a way for some people with ill will to just throw away players they just don't like.

Also, a good way to prevent this would be to raise severly the conditions to be mentor. The current sytem is so easy to grind that I start thinking even bots can reach it. The problem with this one, is that there are also some mentors with good will that have for example other interest than grinding dungeon to get the status (crafting for example) that will be thrown out of novice chat.

On Lich, we managed to keep the Novice Chat pretty good till now (I've heard that it isn't the case in some other servers), and we'd like to keep it helpful for new players. We need to be able to prevent those advertising by ourselves. Some of the suggestions have their pro and cons, but there may be some way to make them possible. I'd like to hear your suggestions.