Email [email protected]. Messages are read, but there is no guaranteed response time.
What to include
For a data error (wrong type, wrong base stat, a Pokémon missing from a game's list, a wrong version exclusive): the Pokémon's name and form, the game you had selected, and what you expected to see.
For a bug: the page address, your browser and device, and what you did before the problem appeared. If the team builder shows a wrong result, paste the share link so the exact team can be reproduced.
For a feature request: what you were trying to do and where the current tool stopped short. Requests that come up often are kept on a list and shape what gets built next.
Please do not send anything you consider confidential; this address is a normal mailbox.