According to my book "The Access 95 Bible", an Access database's maximum password size is 16 bytes of alphanumeric characters. A former coworker confirmed that tidbit for earlier versions also.

Still, taking every possible printable character in the ASCII Character Codes chart, starting with decimal 32 (the space character) and ending with decimal 126 (the tilde character) yields 126 - 32 = 94 raised to the 16th power means that I'll be dust in my coffin long before a brute force attempt on one machine will successfully discover the correct password for an Access database file.