We did sent an email about the new Forums, and contacted one by one the key people on the old forums. We also are working closely with the guys of the Zeta Alliance, http://www.zetalliance.org/
a Community about Zimbra, but people for different reasons didn't came back, or they moved to another solution so they didn't need to come back, or change their role at work, etc.
We have still a good contributors you can see on the forum, L. Mark Stone, phoenix, JDunphy is doing a great job providing amazing answers, etc, you can find them by the badges.
The zimbra forums have the same amount of weekly topics or even more than before, even in the old good days, and around the same number of replies, and non-replies with topics without an answer.
To improve this Forums I see multiple things we can do:
- The Zimbra Engineers and Developers, and even Sales, come twice per week and reply to their different Sub-forums
- The Zetalliance finally to contribute to the forums, I've requested multiple times
- Prepare a blog post and send, another, massive email like you said
On my side, I'm replying as much as I can and trying to help always.
Let me work on the points and I will let you know.
Best regards, it's good to have you back cyber7