I've received an e-mail of a colleague that I meet once. He wrote as introduction, "I hope you're doing well" and then he continued directly with the matter of the mail.
I would like to use some kind of similar introduction, but it cannot really be very personal, as we don't know each other so well (I thought about using "I'm glad to hear from you"... but probably he will not believe it :) )
The recipient of my mail is a colleague and we have never worked together, but now we will work in the same project. He is an Englishman and he is extremely correct.