I noticed today that an application that I'm working with that sends automatic notifications with links (a button with embedded link) in an html format seems to be causing issues in OWA 2010.  If we try to click on the link from OWA it appears to apply some crazy formatting to the link, almost like a redirect, and winds up giving us a 404 error.  If I open up the same email in Outlook 2013 (desktop client) it works just fine.  Other links that are not formatted with html work just fine.  Has anyone ever seen this?

• Edited by Blake Jason Wednesday, February 11, 2015 3:36 AM

Hi Jason,

According to your description, I understand that it will auto redirect and return 404 error when you open a link in OWA with HTML format, and it works well in Outlook client.
If I misunderstand your concern, please do not hesitate to let me know.

After my test, when I open a hyperlink in OWA, it will automatic redirect to current CAS server then jump to correct URL.
Please try to manual copy this hyperlink and open it on a new tap. Ensure the authentication of OWA, you can run below link to double check:
Get-OwaVirtualDirectory | FL Identity,*auth*

More details please refer to Understanding Authentication for Outlook Web App:
https://technet.microsoft.com/en-us/library/bb430796(v=exchg.141).aspx

Best Regards,
Allen Wang