Create and Update mailing list

Have a a mailing list of 700 individuals who work at large corporations.

The source website for the mailing list now has 2,000 individuals on it ( with their addresses)

I need someone to

- Put the 2,000 individuals on the website into mailing list format for me
- Cross reference these to the existing 700 I have , delete duplicates
- Update the contact details those which are not duplicates and not on the 2,000 on the website ( their offices will have changed and some have moved work places)

The mailing list has a different column for salutations, first name ,last name and for each line of the address