Email is best. I answer it myself.

Useful things to put in the first line

• A deal. What is being bought or sold, when it signs, and what worries you.
• A recovery. Where you are, and whether you need a second opinion or a hand.
• A cost programme. The target, the deadline, what has been tried.
• A board seat. The company, the stage, why now.
• A leader stepping up. Who, and what the step is.

Introduced by someone we both know? Say who. I will tell you honestly if I am not the right person.