Legal Question in Credit and Debt Law in Pennsylvania

I don't know what you are trying to do so I cannot possibly give an opinion as to the legitimacy of it.

Your question makes no sense as phrased. Anything is legal if it is not otherwise prohibited/classed as crime by federal or state law.

The question you should be asking is whether the new document you are creating is legally enforceable?

The answer to that is it depends. If you are talking about a loan, the proper document is not cut and pasted emails but a promissory note. Free samples abound online. At the most basic, it has to identify the lender and borrower, the amount of money loaned, and whether it will be repaid in a lump sum on demand or in installments over time. If the loan is to be repaid in installments, the note should specify an interest rate that is reasonable and which does not violate the usury laws of your state. The note should be signed by both the borrower and lender, but at the very least it should be signed by the borrower to be enforceable.

If you have lent money foolishly without getting a signed promissory note that does not mean you could not sue if the borrower did not repay. However, it does make proof of liability more difficult. While any transactions over $500 should be in writing and signed by the borrower, partial repayment or other conduct may overcome the requirement of a writing. Examples of conduct may be part repayment by check or money order on which "loan repayment" is written in the memo line. If you have a email document from the person who borrowed acknowledging the loan that may be persuasive too.

If you want more advice, then you need to either pay a local attorney to review what you are trying to do or you need to re-post your question with all of the relevant information so that an attorney may give you more guidance.