Hasbro’s Em@il Games Scrabble does not come with a dictionary. Instead, checking words for validity is done by the server, and only when a player challenges a play. This was probably for a few reasons – reducing the client download size, allowing Hasbro to update it as needed, and as a safeguard to keep the word list out of public circulation. Greg Kennedy writes:

This means I need to provide my own dictionary for Hasbro PBEM Proxy to support the game. It seemed a simple enough problem: just get a word list from somewhere, and hook it up. But which one? I started by using CSW21, the latest (at the time) list of competitively accepted words. Yet this bothered me as it seems anachronistic: the game released on Feb. 5, 1999, so shouldn’t the word list be equally contemporary?

Thus another journey into software archaeology. “What dictionary were people using in 1999?” turns out to be a complicated question, due to the fact that different lists were used for casual vs tournament play, US vs UK, short vs long words, etc. and unification of these was not really a priority at the time. Plus, some of the word lists remain unavailable unless you were a paying member of NASPA or another Scrabble professional organization.

See Greg’s analysis and solutions in the post here.