Outlook 2016 For Mac Not Authenticating

We are hoping to role out Office 2016 for Mac and use Outlook 2016 for accessing Mail. We have Exchange Server 2010 Version:.002. We use Server 2012 for our Domain controllers and Kerberos auth is working fine for logging into Macs.

In of this article, we discussed symptoms of Mac Mail unable to connect to Exchange 2016 servers through KEMP LoadMaster load balancers. We also discussed troubleshooting steps that addressed the issue of ExRCA.com unable to pass EWS tests, however, we stopped there since Mac Mail failed to connect despite ExRCA EWS tests passed. Let’s see what we can do to get the Mac Mail to connect successfully to Exchange servers. Since we addressed the 100-continue handling in of this article, ExRCA tests did not indicate any more issues.

Microsoft Outlook for Mac did not have issue connecting to Exchange even before we changed 100-continue handling to be RFC-7231 compliant. At this point, I decided to look at the network trace. Looking at the trace captured using Wireshark on the client machine, I noticed the following HTTP dialog: POST /ews/exchange.asmx 401 Unauthorized POST /ews/exchange.asmx 200 OK POST /ews/exchange.asmx 401 Unauthorized POST /ews/exchange.asmx 401 Unauthorized POST /ews/exchange.asmx 400 Bad Request Notice how initial dialog included challenge response for NTLM authentication and ended with 200 OK. At this point Mac Mail client started with another POST operation to EWS. However, this time the pattern followed multiple 401 responses from server and ended with 400.

When comparing that with Outlook for Mac, the pattern looked like the following: POST /ews/exchange.asmx 401 Unauthorized POST /ews/exchange.asmx 401 Unauthorized POST /ews/exchange.asmx 200 OK Notice how the pattern looks similar to Mac Mail’s second POST request, however, it ends with 200 OK. The response included data that was requested by POST operation. I needed to correlate this with the data being received on the Exchange server. Due to newer ciphers which use PFS (Perfect Forward Secrecy) I couldn’t decrypt data being received from load balancer by the server despite having the private key used to encrypt the information. I was able to decrypt client side traffic due to load balancer configuration of ciphers that didn’t use PFS.

I don’t recommend this configuration in production and KEMP LoadMaster default setup uses more secure ciphers. I had it configured this way only for troubleshooting purpose in my lab and no production data was in flight during testing. I was now facing the issue of capturing the headers from the server side. One way to address this is to configure list of ciphers used by server similar to what I had done on KEMP LoadMaster. However, in my test that did not work for some reason. I decided to use failed request tracing in IIS (big thanks to my Microsoft colleague Brad Hughes for the hint).

Modified: August 16th, 2018 Are you looking for a solution to fix Outlook 2016 for Mac keeps asking for password error? Then no look further! This article will explain a very effective method to resolve this issue. Keep reading this post till the end. Most of the times, when Mac Outlook 2011 users enter the credentials while making a connection with Office 365. It will stop the authentication process and keeps asking for the password again and again. This problem occurs in Mac Outlook because of corruption in Keychain Access program.

Basically, it is a default application in Mac and used to save the information of email account login. So, whenever the problem arises in Keychain Access, Outlook 2016 for Mac Keeps asking for password office 365. Therefore, in this write-up, we are going to provide a relevant solution that will repair this issue easily. I am working in a reputed firm where we are using Mac system. Recently, some of our organization system attacked by the virus.

Really would appreciate your help. Cad drawing for mac.

The issue was easily resolved by formatting the Mac system. But, after the fix, when the employees connected to Exchange using Outlook 2016 Mac, it will repeatedly ask for the password. Also, I checked the profile configuration, they are all fine.

Thus, I really do not understand, is this problem occurs due to a bug. If any of my technical friends know the exact reason and solution for this error, then please tell me. Any help would be appreciated!”. Also Read: Now, let us know about the correct reason behind this glitch.

Why Does Mac Outlook 2016 Keep Asking For Password: Know the Reason As all, we know that Mac operating system is the best machine in terms of security and reliability among the globe. Adding to it, it provides an inbuilt password management program known as Keychain Access. Its function is to save all the password of Mac-based program like Mac Outlook password on the machine. However, due to unexpected reasons, Keychain Access can be easily damaged or corrupted and it will disturb entire normal work flow. Similarly, in Mac Outlook, lots of duplicate tokens will appear in Keychain due to corruption. Unfortunately, it will leads to a complex situation, and confused with the authentic credentials.