@Piru:
It's funny how snide remarks are taken for signs of intelligence these days.
What you wrote is neither helpful nor constructive, because simply: I already know that information and it doesn't help solve my problem which happens to be post-facto regarding the migration. For whatever reason what happened, happened. What can you do or say that will actually have a positive material difference in my current situation?
Anyhow, none of the above cases you mentioned took place. The data is still existent, just not available due to changes in interface/configuration. Furthermore the previous system didn't offer any exporting functionality, so if you wanted to keep a pmail you'd have to copy and paste the text, which beyond arduous, if I recall correctly weren't even complete (containing detail headers, the sent messages, etc. like emails).
Oh, and most importantly: anyone servicing thousands clients, for free or not, ought to keep backups too. So if the data's gone, that is a primarily failure of the service provider. And let's not start with this is a free service and all that mumbojumbo, because as everyone understands a forum is nothing without content and content is added by the members, therefore it's not a "one way" service. It's an ecosystem.
@Wayne:
If the data is around, would it be possible to get a raw dump of them? At the very least the pmails. Who can help me here? Pmails are theoretically text only and couldn't be possibly taking that much space. The photos I have on my disks as that's where they originated, but pmails didn't.