Your mail server certificate is invalid error

Anonymous
2018-03-03T15:59:06+00:00

I am attempting to use Outlook on my android phone.  When I attempt to add my email account to outlook (on my phone) I get an error that says:  Your mail certificate is invalid.  Would you like to login anyway.   PLEASE HELP!!!!

Outlook | Outlook for mobile | Outlook for Android | For business

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  1. Anonymous
    2018-04-26T18:25:51+00:00

    Unfortunately, still not working for us.

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  2. Anonymous
    2018-04-26T21:04:52+00:00

    Using a Godaddy certificate.  20 phones.....same problem.  Outlook version 2.74.0 on iphone.  Can not find a newer version in the app store.

    Microsoft.......PLEASE FIX!

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  3. Anonymous
    2018-04-26T21:45:18+00:00

    It seems to be as I suspected, a TLS issue.

    A co-worker submitted a support case to Microsoft from within the Outlook app. They checked our server and confirmed, as I already knew, that it doesn't support TLS 1.2.  They stated their app only supports TLS 1.2.

    Exchange 2007 does not support TLS 1.2 and Exchange 2010 doesn't support it unless it is updated to Update Rollup 9 for Exchange Server 2010 Service Pack 3.

    We could not immediately get an answer as to whether they had just dropped support for TLS 1.0. So we're going to have to use the native e-mail apps for now until the upgrade of our Exchange server is complete.

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  4. Anonymous
    2018-04-26T22:06:10+00:00

    Not sure that it's that cut and dry...

    We did some packet sniffing and found that my device wasn't even trying to get to our on-prem server...its going back and forth with a Microsoft IP and they complain about the TLSv1.2 handshake and then they just end all communication.

    We don't see ANY traffic to our webmail proxy coming in from Intune at all...

    Seems like perhaps the APP got updated to TLS1.2, but their servers didn't?  Or the servers on their end that handle the on-prem Exchange communications?

    According to HERE , O365 isn't even using TLS1.2 yet

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  5. Anonymous
    2018-04-26T22:19:34+00:00

    I'm running Exchange 2013 internally.

    Currently on CU17.  Outlook client broke.

    I'm now in the process of upgrading to the latest CU20 (released March 2018).

    Stay tuned....

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