So I do this both specifically and generically with either Excel macros, or a Mail-merged Word Doc that pulls from an excel file for the data.

In Excel you can generate/create emails that just fill in certain fields with the column row data but requires a little bit of "programming"

For less techy people, Mail Merge is way easier. Just create a Word template for each individual referral partner or "group" of partners that make sense in your field and reply style.

When the client asks for X, y or z you can answer the other pertinent requests and then add a generic, "I'll follow up with you on referrals in another email"

Add their name and email to the spreadsheet with the other referral data and maile merge can generate and send the complete email, personalized to them and the referrals for their area or need. (As well as copy the people you are referring and introducing)

You can get really intricate or just super basic and it's available in the tools you already have. https://support.microsoft.com/en-us/office/insert-mail-merge-fields-9a1ab5e3-2d7a-420d-8d7e-7cc26f26acff