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Exchange 2013 CU14 - MAPI over HTTP - Outlook 2016 Prompts For Password. Is This Normal?

    Question

  • My second time trying to turn on MAPI over HTTP to replace RPC on Exchange 2013. Up to date on .net and on the second to the last CU - CU14.

    My users currently (RPC) do not get asked for a password whether they are on the internal network, out of the office over the internet connected or not connect to the VPN.  Outlook 2016 just works.  BTW, Outlook 2016 is up to date as of today, March 19, 2017.

    I do not have Alternative Service Credentials (Kerberos) set up. 

    But whenever I turn on MAPI for the company, my account and an end user account (2 different Domain Joined laptops) ask for credentials.

    More testing is needed, but I think I have it down to asking the first time and not multiple times like when I first did this a couple of months ago.  I played around with the authentication settings for the MAPI virtual directory.  Last time I just had Negotiate and this time I tested with NTLM, Oauth, and Negotiate all set.

    So my question is for those of you on Exchange 2013 or Exchange 2016 on Premises and are using MAPI over HTTP with Outlook 2016, do your users have to put in a password when they start Outlook?  Did this just happen when you switched over and that was it?  Or do they have to do it every time their domain password changes and make sure they mark the remember my password box?

    Seems a step back.  I'd like to get MAPI going so I'll be more comfortable upgrading to Exchange 2016 soon, in preparation for a hybrid setup with Exchange Online.  I already have SharePoint Online and Skype For Business, etc. and am using the AD Connect with password sync for my users...but I don't have SSO set up.  (2nd question - when a user's mailbox is on Exchange Online in a Hybrid password sync w/o SSO environment, do they get prompted by Outlook? I know - wrong forum.  Just thought I'd sneak it in there.)

    I see many people complaining online about multiple password prompts and they either choose to keep RPC or they get it down to one prompt and live with it.  But I assume if that password is stored in Windows Credential Manager, it will have to be updated when the domain password changes - ie, Outlook will ask for the new password.  Because this seems like such a step back, if in fact this is by design, then I'm assuming it's because this is how it works on Exchange Online.

    Thanks for reading. 


    • Edited by EugB3 Monday, March 20, 2017 3:17 AM
    Monday, March 20, 2017 3:14 AM

All replies

  • Exchange 2013 doesn't support MAPI over RPC.  That went away when you retired your last Exchange 2007 or 2010 server.  Exchange 2013 uses RPC-over-HTTPS.  Are you trying to replace Outlook Anywhere, RPC-over-HTTPS with MAPI-over-HTTP?


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    Monday, March 20, 2017 3:53 AM
    Moderator
  • Exchange 2013 doesn't support MAPI over RPC.  That went away when you retired your last Exchange 2007 or 2010 server.  Exchange 2013 uses RPC-over-HTTPS.  Are you trying to replace Outlook Anywhere, RPC-over-HTTPS with MAPI-over-HTTP?


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!

    Apologies, yes.  I am trying to go from RPC/https to MAPI/HTTPS.

    Tonight I got Kerberos configured and inside the office network all is good.  After a reboot, switching to an external network, Outlook prompts for credentials and needs a password if I cancel it.

    I'm trying to figure out if this is how it is for everyone or if I'm doing something wrong.

    I found this thread:

    https://social.technet.microsoft.com/Forums/en-US/0dab81d0-a0b2-4483-a7bd-623179d25dc2/mapi-over-http-outlook-prompting-for-credentials?forum=exchangesvrclients

    This guy removed negotiate from autodiscover and EWS virtual directories and that fixed him up.  My settings look like his before his change.  You were on that thread...what did you think about his solution?

    • Edited by EugB3 Tuesday, March 21, 2017 1:34 AM Added found thread info
    Tuesday, March 21, 2017 1:12 AM