How configure TLS only between two domains in Exchange Server 2013

Posted on 2016-09-15
Medium Priority
Last Modified: 2016-09-19
I need configure in Exchange Server 2013 communication TLS only between 2 domains. The communication is with our server and other server "client".

Best regards.
Question by:ccedillo
  • 2
LVL 49

Expert Comment

ID: 41800946
Opportunistic tls is enabled by default on all new(ish) email servers, so chances are you don't need to do anything tls is already being used

Author Comment

ID: 41801025
Hello Akhater. Thanks for your answer.

I am check in www.checktls.com and the result is:

test stage and result : TLS is not an option on this server

[000.070]  Connected to server  
[000.216] <-- 220 smg.macf.com.mx ESMTP mail.macf.com.mx  
[000.216]  We are allowed to connect  
[000.216] --> EHLO checktls.com  
[000.287] <-- 250-smg.macf.com.mx says EHLO to
250 SIZE 35840000  
[000.288]  We can use this server  
[000.288]  TLS is not an option on this server  
[000.288] --> MAIL FROM:<test@assuretls.checktls.com>  
[000.360] <-- 250 2.0.0 MAIL FROM accepted  
[000.360]  Sender is OK  
[000.360] --> RCPT TO:<ccedillo@macf.com.mx>  
[000.436] <-- 250 2.0.0 RCPT TO accepted  
[000.436]  Recipient OK, E-mail address proofed  
[000.437] --> QUIT  
[000.508] <-- 221 2.3.0 smg.macf.com.mx closing connection
LVL 49

Accepted Solution

Akhater earned 2000 total points
ID: 41801071
If that's the receiving side smtp server then the only way is to contact the it responsible for that domain and let them enable tls on their server. Nothing to do on exchange side
LVL 63

Expert Comment

by:Simon Butler (Sembee)
ID: 41801286
If the other side or you require the use of TLS, then you need to configure Mutual TLS. That ensures that the traffic goes over TLS and is unable to fall back. While it is true that Exchange does opportunist TLS, that allows fall back.

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