We are reading Funny in Farsi on Skype. You should read with us, Nini.

"more than sufficient" basically means "more than enough". It is typically said as a form of gratitude for someone's generosity. For example: "The money you donated to the school is more than sufficient! We'll be able to give every student their own personal laptop now!"

If something is sufficient, it means it is enough. So more than sufficient would mean more than needed. However, I have never heard the phrase more than sufficient being spoken but that's what I would guess it means.