I upgraded to the release version of Opera 9.50 last night. All seemed to go smoothly: it imported my bookmarks, contacts and email account details without difficulty. Then it imported all my emails . . . and promptly zapped the email bodies. I am now the proud owner of several years of email subject lines! Aaaargh!!!
Actually it's not quite that bad. The original emails are still there on the hard disk. But when I reverted to the beta version the message bodies had disappeared there as well. I can still read them with a file viewer I happen to have. My problem is finding anything. I have spent more time than I can really afford trying to find some way of indexing the old emails so I can access anything I need to refer to.
Meanwhile the disaster has forced me to migrate to Gmail. My email addresses haven't changed but they now point to my Gmail accoint.
Update: With a bit of tweaking, Copernic can be made to index Opera .mbs files. So now I can read my old emails. And a handy little base64 decoder I happen to have even allows me to retrieve any email attachments. So life has returned to normal . . . except that my faith in Opera as a browser/email program has taken quite a battering. The new version of Firefox is released next week. Perhaps I'll take a look at that.