I am contacting you because you have been a tremendous help to Both Co. in the past (with regards to helping us coordinate Matt Shipleys internship and the guidance you have given us).
Furthermore, I and the rest of the leadership team at Both Co. feel that your professional experience makes you more than qualified to keep Both Co. in line with its mission.
With this all taken into consideration, I have the great pleasure of asking you if you would be willing to consider joining the board of directors for Both Co.
I know it is a big favor to ask of you, but I hope that you might be able to meet with me and discuss this opportunity in detail.