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Bill Smyth
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Exchange Server 2013 and official TLS 1.1 / 1.2 support for EWS?

I see SMTP now supports TLS 1.1 & 1.2 in Exchange 2013 with Cumulative Update 8.  However, I cannot find anything from Microsoft that states whether Exchange Web Services (EWS) support TLS beyond 1.0 or not. Would anyone have a link to what TLS versions 2013 supports in EWS? I just cannot find a statement or feature support that lists it.  

I would be using Server 2012 R2 which supports TLs 1.1 and 1.2 at the OS level. SO its just the Exchange App I am concerned with.

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Bill Smyth

8/22/2022 - Mon
Amit Kumar

I think, you should get this checked by any external vulnerability solution, it will give you report if your IIS/web services  support weak ciphers and SSL3.0/TLS 1.0.

If your IIS is restricted to use TLS 1.1/2 then any application which is configured in IIS will use only restricted ciphers.  

You can use this tool to restrict your IIS to use strong ciphers as well as. One more article from IIS forum same tool is suggested.
Jian An Lim

Jian An Lim

IIS is POODLE free if you follow Microsoft security advice,


If you need any support, you should follow the tips in Support section.

Your help has saved me hundreds of hours of internet surfing.
Bill Smyth

This question is about planning our upgrade away from Exchange 2010, not fixing it. Our 2010 server is fully patched and the protocols are configured as FIPS 1. Secure SMTP is OK now, but EWS is stuck at TLS 1.0 and that seems unlikely to change.

We were looking to migrate to Exchange 2013 in the next month or two. But we cannot determine whether EWS in Exchange 2013 supports TLS 1.1/1.2 or not?  If not, then a move to 2013 may not meet our requirements and we will need to look at other possibilities.
Jian An Lim

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Bill Smyth

This is what I seem to find as well. I have found other with 2013 listing issues with this support lacking as well. No word from Microsoft on EWS supporting 1.1/1.2 in the future anywhere I have looked.
Bill Smyth

Follow Up
TLS 1.1/1.2 support for HTTP and SMTP (but not POP3 or IMAP) was added in Update Rollup 9 for Microsoft Exchange Server 2010 Service Pack 3 (SP3) was released on March 17, 2015.  See: https://support.microsoft.com/en-us/kb/3030085 

Support for TLS 1.1/1.2 was also added in Exchange 2013 CU8.  

Exchange 2016 and Office 365 appear to support TLS 1.1/1.2 on all services from what I have read in a few places, but I do not have an official Microsoft link to verify that yet.

The Technet blog post "Exchange TLS & SSL Best Practices" was published on 27 Jul 2015 with details on TLS support, requirements and recommendations for each service.
See: http://blogs.technet.com/b/exchange/archive/2015/07/27/exchange-tls-amp-ssl-best-practices.aspx 

There are some few pre-requisites to this working end to end.
Exchange must running on Windows Server 2008 R2 (2008 must be R2) or above.
The MAPI client must run on Windows 8.1 or later.
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