Applescript help?

I think this is the right place to ask this. I am looking for someone who can help me with writing what I imagine is a simple Applescript. I know html and css, but this is above my head. I typed a letter in Pages that needs to be emailed out to a multitude of people (500+). I used Mail Merge to customize the content of each letter, but it merged into one VERY large file. I want to split the file (which I have now converted to .txt which I imagine makes it easier to work with) at my signature (as my name [Jesse] only appears at the very end of the document). Can anyone help me? If not, pointing me in the right direction of what to learn would be awesome. However, as I will never have to do this again and really don't wanna have to learn the whole Applescript language for a one-time project. Thanks in advance!