I've got a huge md5 suppression file (3gb) and I want to compare it to my mail list and only pull out entries that are the same in each file, so I don't have to try inserting the entire md5 suppression file into my database. The suppression file is just each md5 on a line. The mail file is email,md5. I'm pretty sure this is a simple thing to do with grep, but not sure where to start. Any input is much appreciated.... Thanks!