Are you trying to do this in a browser? Use a real email client, such
as Thunderbird. With it you can sort as far back as you like. You can
also use it to archive mail by year. Configure Thunderbird to use IMAP,
to keep everything in sync.
charles meyer wrote
> Gotta' use webmail at work - not TB.
But, why try to move it? Just push into archive in your Gmail account--that
retains the pretty functional search that Gmail implements.
Otherwise you can export/dump the mail using Google's Takeout services  ,
results in --mbox--formated mail archive, and then use a portable reader (no
install) to review. Something like MBox Viewer as an example:
Or there are more robust mbox file viewers that would require an
installation. Many free, but offering fee based advanced support.
Working in LibreOffice would probably require parsing the .mbox files and
loading to Calc cells, or better to SQL tables with a Base form--but search
will be an issue. The Apache Tika project offers an mbox parser in Java to
extract meta from the mbox for fielded data loads. But I don't think there
is anything turn-key for either Calc or Base.