The current development schedule for future versions of Mulberry is here . We are in the process of automating our Feature Request system so you can see on the web what other people have asked for previously. I'd like to import my own addressbook, but I need to change it to a compatible format. I have mail on multiple IMAP servers. We've modified the user interface a little bit for this in version 1.2 to make this more clear.
Many people have to send mail back and forth to users of older mail systems.
It's really crucial that they be able to not only read attachments sent by these systems, but be able to send back attachments in the formats the poor folks afflicted with the older programs have to live with. If you're using Internet Config on the Mac, IC will look up certain MIME mappings to MacOS file creators and types. IC comes with a large set of default 'out of the box' mappings, many of which don't particularly jibe with popular user settings. Return receipts are an extremely deceptive, unreliable feature in internet mail, and we feel putting them in is actually doing users a disservice. There is currently no acceptable foolproof standard for requiring return receipts.