Contact
Before you write: the user guide is public, and every page ends with the real limits of that part of the product. It answers most of what you would otherwise be asking us. If it does not, pick whichever address below fits.
Sales, partnerships, anything else
Whether it fits, migrating from something else, or working together. Tell us roughly what your business does and what you're using today.
Support
Anything account-specific. Include your company name and what you were doing at the time, which saves us both a round trip.
Something wrong in the guide
Tell us which page. We maintain the guide against the product itself, so a page that's drifted is a bug we want to hear about.
Already a customer?
Raise it from inside the product instead. A ticket carries your company and the screen you were on, so nobody has to start by asking which account you mean.