Messaging app now broken - migration from on premises to O365 RRS feed

  • Question

  • We have an internally written messaging service (C# app) that uses just standard SMTP to send e-mail messages from various other applications within our organization. It utilizes three different e-mails depending on the situation.  For instance, we have a home grown Help Desk application that is served as a web application in our sharepoint environment.  When a user adds a ticket, they get an e-mail response from  There are two other e-mails set to do other things also.  One is EDI and another SMADONOTREPLY.

    We recently migrated from on-prem Exchange to the online O365 environment.  And now we are getting this error message with TWO of the addresses: "

    SendMessage Failed:   Autodiscover blocked a potentially insecure redirection to To allow   Autodiscover to follow the redirection, use the AutodiscoverUrl(string,   AutodiscoverRedirectionUrlValidationCallback) overload."

    One of the addresses (the smadonotreply) was not converted yet and still works.  The other two get this autodiscover error.

    How can we fix this?


    Brad Allison

    Thursday, January 26, 2017 2:46 PM