Squirrelmail / Apache / 403 Forbidden problem

[Bob Brennan]

Trying to access Squirrelmail from another computer on the Internet -
I have set all the config options, followed instructions, googled and
searched archived lists, visited squirrelmail.org but can't find an
answer to this other than "squirrelmail is restricted to the local
machine by default". I changed the server name in the conf file as
instructed and can get the /webmail/ directory as
http://server-name/webmail/, but only from the local machine.

Any attempt to connect to http://server-name/webmail/ other than the
local machine results in "403 Forbidden - You don't have permission to
access /webmail/ on this server." The server log file shows "[time]
[error] [client x.x.x.x] Directory index forbidden by rule:
/usr/share/squirrelmail/"

I've searched both the Squirrelmail and Apache conf files for such a
"rule" but nothing. Any ideas/pointers/similar experiences?

Thanks,
bob