Can I configure Outlook Web Access (OWA) 2003 to use English as the default spell-checking language?
OWA 2003's spell-checking module is a godsend for people who have trouble spelling, but it isn't as flexible as the Outlook or Microsoft Word spell-checker. Currently, the OWA 2003 module offers no way to apply default settings for most of its features, including setting a default spell-checking language and specifying whether the spell-checker will ignore uppercase or mixed alphanumeric words. Even worse, you can't customize OWA 2003's spelling dictionaries. You can, however, navigate to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWeb\OWA registry subkey and edit the DisableSpellCheckOnSend value (of type REG_DWORD) to disable spell-checking altogether.