Sudden "The requested web method is unavailable to this caller or application" error trying to retrieve mailboxes from C# application (Exchange Online) RRS feed

  • Question

  • Hello all,

    We have developed an application that retrieves content from users mailboxes in Exchange Online using EWS.  It is working fine in most installations but one client has begun to see the "The requested web method is unavailable to this caller or application"  It seems the offending line is a ExchangeService.GetSeachableMailboxes call.

    The very odd thing is this was working fine for them as well up until a day or two ago when this error started to propagate.  The documentation for this error is largely lacking and we are at a loss on how to go about resolving it.

    Is it possible MS has blocked their access to this functionality?  That seems extraordinarily odd.

    Friday, December 5, 2014 7:16 PM

All replies

  • A few things you might want to check is if the client themselves have blocked EWS access is someway. eg try running

    get-casmailbox MailboxName | fl ews*

    It maybe some administrator has decided to try to restrict access to EWS in some way (maybe for legitimate purposes like try to block external apps like linkedin etc).

    The other thing I would check is because that is a eDiscovery operation check that the Caller has the Discovery Management Role.

    Another easy thing to test would be try testing eDiscovery in EAC and also try using the EWSeditor https://ewseditor.codeplex.com/ to test this outside of your code.


    Monday, December 8, 2014 4:13 AM