Chad... When on the internal LAN and accessing the mail-in database from the notes client using "open other mail" it works fine.  When accessing the mail-in database using iNotes via a web browser it generates the error.  Using a web browser to launch:  https://server.domain.com plants me in the full desktop with everything functioning properly except the mail-in database.  If I launch:  https://server.domain.com/mail/database.nsf, it opens the mail-in database fine for reading and sending email except the interface it displays needs a lot of work.

I checked the properties of the mail-in database and the properties of the database are:   For Web Access... Javascript is checked but the next four settings are unchecked.  For the bottom 6 selections, disable background agents is unchecked, Allow use of stored forms is checked and the remaining 4 items are unchecked.