Use a database
I automatically prepare "Thank you" letters for donations.
Of course the letters include the date and amount of the donation, obtained from the database where I enter each donation. Some sentences are only included for larger donations. Letters are only sent to people who have made a new donation.
The letters have a number of alternative paragraphs based on the fund for which the donation was made, whether the donor is domestic or foreign, etc.
I use dBase for DOS and have written a program (in dBase) which creates the personalized letters. dBase for DOS is obviously a dinosaur but is rock-solid. I don't know whether any current database system has as much flexibility. Most newer databases would require a separate program to prepare the letters.
Probably the most useful thing to learn from my approach is to maintain and update a database of clients to whom you need to send letters. My database has fields where the current donation is entered. Earlier donation details are kept in the "historical" section of each record and the details of the new donation are automatically moved to that section after the letter is created.
You might find that "mail merge" could be made to do what you require.
Last edited by seacue; 16th August 2013 at 11:08.