Hi,
I don't know whether this has been suggested before, but how about an e-mail digest that users can subscribe to? Basically users would subscribe to a board and every [insert time period of choice], an e-mail would be sent to the subscribed user listing all the new posts (and perhaps the message bodies too). A couple of other boards that I know of have this feature built in, namely
Gossamer Forum and WWWThreads (I think that's what it's called anyway).
A lot of my board's users have asked for this feature.
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