Sometimes I find myself starting or ending emails with a "thank you" note to appreciate the person on the other side making available in case I need some help. His email may end with something like "Should you need any help, please don't hesitate to contact me".
In my native language we usually write "thank you for your availability". This translation sounds a bit weird to me, and I generally opt for something like "thank you for being so helpful", but the meaning is slightly different because it implies that the person has already helped me in some tangible way.
Is there a sentence commonly used in English to say "thank you for making you available to help should I need it"?