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David Kamp's avatar
David Kamp
Brass Contributor
Apr 20, 2018
Solved

OnPrem SMTP sending to Office 365 Encrypted

I have Internal servers relaying on a "on premise SMTP server" this smtp server has an Office 365 Exchange Connector configured a: From: Your organization's email server To: Office 365 Identity: f...
admin
exchange
office 365
  • VasilMichev's avatar
    VasilMichev
    Apr 23, 2018

    It's generally assumed that when you configure TLS, you would use a certificate associated with specific domain, so that the service can verify the sender. If you use the IP option, you should still be able to toggle the TLS requirement via PowerShell:

     

    Get-InboundConnector Hybrid-In | Set-InboundConnector -RequireTls $true

NunoAriasSilva's avatar
NunoAriasSilva
MVP
Apr 20, 2018
Hi David,
By default when you run Hybrid Configuration Wizard it will configure the TLS base on you certificate by default.
  • David Kamp's avatar
    David Kamp
    Brass Contributor
    Apr 23, 2018
    When I edit my Connector, On the question of: How should Office 365 identify from your Mail server? I am selecting my IP Address and then do not have an Option for TLS and the summary does not indicate TLS.
    • VasilMichev's avatar
      VasilMichev
      MVP
      Apr 23, 2018

      It's generally assumed that when you configure TLS, you would use a certificate associated with specific domain, so that the service can verify the sender. If you use the IP option, you should still be able to toggle the TLS requirement via PowerShell:

       

      Get-InboundConnector Hybrid-In | Set-InboundConnector -RequireTls $true

      • David Kamp's avatar
        David Kamp
        Brass Contributor
        Apr 24, 2018

        I ran the command to force TLS, Now Powershell shows "RequireTls: True

        This is the result log file on my smtp server does it look to be secure?

        *****

        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionResponse - 220+CO1NAM03FT006.mail.protection.outlook.com+Microsoft+ESMTP+MAIL+Service+ready+at+Tue,+24+Apr+2018+12:01:14++0000 94 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionCommand EHLO smtp.XYZ.org 94 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionResponse - 250-CO1NAM03FT006.mail.protection.outlook.com+Hello+[XX.XXX.XXX.XXX] 157 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionCommand STARTTLS - 157 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionResponse - 220+2.0.0+SMTP+server+ready 219 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionCommand EHLO smtp.XYZ.org 360 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionResponse - 250-CO1NAM03FT006.mail.protection.outlook.com+Hello+[XX.XXX.XXX.XXX] 407 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionCommand MAIL FROM:<imagenow@XYZ.org>+SIZE=1110 407 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionResponse - 250+2.1.0+Sender+OK 516 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionCommand RCPT TO:<JoeBob@XYZ.com> 516 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionResponse - 250+2.1.5+Recipient+OK 610 SMTP -
        2018-04-24 12:01:14 216.32.181.10 OutboundConnectionCommand BDAT 1110+LAST 610 SMTP -

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