And how do you get the CSV data into fileMaker so that it can use the data?
You should be able to import the data into a table and then use either a relationship between that table and your table of emails or a script that loops through these records and uses the data one at a time to find records in your main table to locate the records for possible deletion.
Ok. I got it. Through import I was able to solve the problem. Just added an additional column and filled each row with 11111. Then while importing targeted emails to the appropriate field (through matching mapping of course) and the 11111 value to Company name field (import this field mapping).
This way company name values were changed only for corresponging email addressing and then through company name field search I was able to track all the entries.
Hope it helps someone!