I feel like this might get abused/spammed by certain people. We already have people spamming chat when an argument gets heated. Maybe some kind of shout command? Actually maybe the mass mailing might be better since it's something you're able to completely ignore rather than seeing it in chat.
I don't think ANYONE uses the mailing system lol.
Why not just advertise the current suggestion that you've made in game chat, server chat, lobby, etc? Similar to when people advertise their twitch links.
The character limit in GunZ is already short enough. Unless there's a hyperlink feature implemented into chat.
Why not just have an auto message everytime you log in mentioning the forums website/encouraging your suggestions?
"Don't forget to be a part of our community at *link*. We also encourage your feedback and suggestions over on the forums as well!"