I am in the process of migrating some users out of our Exchange infra and I am having a small issue with auto-discovery.
Basically, till recently our exchange server was servicing two different public domains (say domain.com and contoso.com) for a single internal domain (say domain.local).
We have provisioned a new, external, unrelated server for contoso.com. Mails are flowing there, all is fine... except that I can not set up domain-joined machines to auto-discover the new server (non-domain machines are working ok).
I have checked that our DNS does not handle any requests for contoso.com - so Outlook (2013), when within a domain, discovers the exchange server in some other way that I can't figure out before looking up the DNS autodiscovery records...
Any idea ?