Recently I had to find a certain email message (which had an attachment) and after couple of quick scans I checked to see if Gmail had an option to search for messages with attachments. Sure enough, there was one: "from:xyz has:attachment". It shows all conversations with messages from xyz having an attachment.
You can also search for a specific filename using "filename:abc.txt". One thing I noticed was if you are looking for an attachment named abc2.txt or 4abc.txt, then searching with "filename:abc" doesn't bring it up; you have to search for "filename:abc2" or "filename:4abc" - really??
For the full range of search options in Gmail, check out their help page: https://mail.google.com/support/bin/answer.py?hl=en&answer=7190
You can also search for a specific filename using "filename:abc.txt". One thing I noticed was if you are looking for an attachment named abc2.txt or 4abc.txt, then searching with "filename:abc" doesn't bring it up; you have to search for "filename:abc2" or "filename:4abc" - really??
For the full range of search options in Gmail, check out their help page: https://mail.google.com/support/bin/answer.py?hl=en&answer=7190
