[cstrat]

You can use the filter tool to sequentially use rules to apply labels to emails from certain senders. Having labels makes searching/sorting much easier.

[jman1]

Any suggestions on how I can get a list of distinct email addresses from which I have received emails ? Kinda like a select distinct on db table ?

[hakaaak]

Exporting and importing contacts as csv: http://support.google.com/mail/bin/answer.py?hl=en&answe...

You could then manipulate that file to hand remove duplicates, could use A2=A1 type formula in a spreadsheet and fill down to find dupes, copy relevant column to text file and sort and uniq in *nix: http://linux.about.com/library/cmd/blcmdl1_uniq.htm

Merging and mass merging Gmail contacts: http://support.google.com/mail/bin/answer.py?hl=en&answe...

You could also use Thunderbird. A few t-bird plugins will let you do things like remove dupes and sync with Gmail.

As for cleaning your inbox though, I would see this as an opportunity to write a script in Ruby that uses IMAP to automate your scrape and purge: http://www.ruby-doc.org/stdlib-1.9.3/libdoc/net/imap/rdoc/Ne... Or whatever other language you'd like to use. I just like Ruby, but since it might involve a lot of text parsing, maybe Perl would be a good choice: http://search.cpan.org/~djkernen/Mail-IMAPClient/IMAPClient....

And then GPLv3 your script, put it on GitHub, use a default GitHub template to create a nice looking site for it, and post the link back to HN with the cool doc saying how to use it.