i cannot remember i setup the autoconfig/autodiscover for you, sorry.
By default, autoconfig and autodiscover (setup by iRedMail team) uses same config file /opt/www/autoconfig/config.inc.php, it means they get same settings and return same settings to clients.
In your case, there're 2 possible solutions:
- Configure both Outlook and Thunderbird to use port 995+SSL.
- Modify the /opt/www/autoconfig/{autoconfig,autodiscover}.php, load different config files with different settings.