An anonymous reader writes "I have kept every email I have ever sent or received since 1990, with the exception of junk mail (though I kept a lot of that as well). I have migrated my emails faithfully from Unix mail, to Eudora, to Outlook, to Thunderbird and Entourage, though I have left much of the older stuff in Outlook PST files. To make my life easier I would now like to merge all the emails back into a single searchable archive — just because I can. But there are a few problems: a) Moving them between email systems is SLOW; while the data is only a few GB, it is hundred of thousands of emails and all of the email systems I have tried take forever to process the data. b) Some email systems (i.e. Outlook) become very sluggish when their database goes over a certain size. c) I don't want to leave them in a proprietary database, as within a few years the format becomes unsupported by the current generation of the software. d) I would like to be able to search the full text, keep the attachments, view HTML emails correctly and follow email chains. e) Because I use multiple operating systems, I would prefer platform independence. f) Since I hope to maintain and add emails for the foreseeable future, I would like to use some form of open standard. So, what would you recommend?"