Hi,
I always used squirrelmail.

My squirrelmail.conf is:

Alias /webmail /usr/share/squirrelmail

<Directory "/usr/share/squirrelmail/plugins/squirrelspell/modules">
  Deny from all
</Directory>

# this section makes squirrelmail use https connections only, for this you
# need to have mod_ssl installed. If you want to use unsecure http
# connections, just remove this section:
<Directory /usr/share/squirrelmail>
  RewriteEngine  on
  RewriteCond    %{HTTPS} !=on
  RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</Directory>

This makes squirrelmail accessible from https://mydomain/webmail

Now I installed roundcube mail and I want to access squirrelmail from
https://mydomain/squirrelmail
and roundcube from
https://mydomain/roundcube

I noticed that if I set the alias
Alias /webmail /usr/share/squirrelmail
or
Alias /webmail /usr/share/roundcube

I can access roundcube and squirrelmail without problem.
If I set this alias
Alias /squirrelmail /usr/share/squirrelmail
and this
Alias /roundcube /usr/share/roundcube

I can't access any webmail.

It seems that the only alias that works ok on my system is /webmail

how this can be possible??

I noticed that if I write this in browser
https://mydomain/squirrelmail/
it works,
if I write
https://mydomain/squirrelmail
without the final slash it doesn't work.

This is very bad for me, how can I access https://mydomain/squirrelmail
without the need of final slash?