IssueTracker

According to MSDN the procedure for Autodiscovery has four different methods to get its settings. Upon one succeeds they are tried in order. Currently Android only implements two.  

E.g. for mail address "test@example.com"

1) ask https://example.com/autodiscover/autodiscover.xml (WORKS)

2) ask https://autodiscover.example.com/autodiscover/autodiscover.xml (WORKS)

3) ask http://autodiscover.example.com/autodiscover/autodiscover.xml (NOT IMPLEMENTED)

note: At this point the GET-request is NOT using SSL therefore it is NOT SENDING any CREDENTIALS. It's only meant to get redirected to a proper SSL-secured site (as in step 1 or 2).

4) ask SRV resource record in DNS for example.com service description (NOT IMPLEMENTED)

for further description, see MSDN, "Finding and calling the Autodiscover service"*


Tested with Android 4.1.2 (custom) and 4.0.3 (Huawei U9200).

Missing possibilities 3) and 4) make Autodiscovery unusable in multi-domain environment. Administrators of non-Android devices usually expect autodiscovery to work cross devices.

Solution: Implement full Autodiscovery (at least step 3)... You can find further details within chapter "Redirect responses"* on how redirection is implemented. You only need to follow a HTTP/1.1 302 Found response to its new "Location: ".

*) http://msdn.microsoft.com/en-us/library/exchange/hh352638%28v=exchg.140%29.aspx



You can see the behaviour also in code:

Current master (https://android.googlesource.com/platform/packages/apps/Exchange/+/master/exchange2/src/com/android/exchange/EasSyncService.java), line 537, states:

// If we fail here, we're out of options, so we let the outer try catch the
// IOException and return null

At this point a simple GET-request without any credentials should be tried against http://autodiscover.example.com/autodiscover/autodiscover.xml to see if a status 302 together with a new Location will be returned to try over the steps before. This feature is different from 451-Redirection which is already implemented.