Thank Someone For a Favour (Letter of Appreciation)

Dear (name),

I just wanted to send you a note to sincerely thank you for all the help you gave me (when?) with (subject).

I was really wondering how I was ever going to solve my problem when you offered your help! It couldn't have come at a better moment.

I know that you are often so busy, as we all are; so that just makes me even more appreciative that you took the time to be able to help me when I needed it.

I hope that you know that I would do the same for you if ever the occasion were to come up, when you need an extra hand with a project or something at work or in the home, whatever it might be, please don't ever hesitate to ask, I most definitely owe you one!

Enjoy your day,

See you soon,

(Your name)