I'm trying to figure out if there is a way I can get the messages from my Yahoogroup and import them in Nabble so my members would have them for historical purposes (to look up past questions, etc.)
Searching the internet, I'm not finding an easy way to get them from Yahoo. The services that were able to get them (yahoo2mbox, Sourceforge's grabyahoogroup & pgoffline) all say they are no longer working due to the recent updates of Yahoogroups to Neo format about a month ago (which is what gave me the final push to get off yahoogroups onto Nabble).
But I do have the digest emails since Jan 1, 2013 in my Outlook 2007 mailbox. I have over 1000 digests which means around 25,000 posts. I'm wondering if there might be a way to take those and use them as an import in Nabble. I could email you one digest to show you what the format of the email is like.