Questions, bug reports, and corrections all land in the same inbox — and everything sent gets read. Pick the topic that fits, and include your email in the message if you'd like a reply; response times vary with volume, but the form is monitored.
Dictionary accuracy is the whole product, so word-list reports get priority. If a result was rejected by your game, or a word you know is valid didn't appear, send the word, the game you were playing, and which dictionary setting you used — the official lists differ by region and revision, and most reports come down to a list boundary, but genuine gaps get fixed. The Scrabble dictionary page explains how the official lists differ if you want to check before writing in.
For short questions and site updates, the UnscrambleX Facebook page is the quickest route. Email works too: [email protected] — the right channel for partnership and advertising inquiries or anything that needs an attachment.
For how the site handles data, see the privacy policy.