Hey there

It was a pleasure working with you. If you get a few minutes, please let me know how we did. For example:

• What stood out the most to you working with us?
• Did we meet your expectations?
• Would you recommend us?

These work as well, if you already use one of them.

And if there's something you want to tell me too, just reply to the message that sent you here and I'll take it from there.

Chris