I am getting a certificate warning. Our 3rd party certificate expires in a month. Is this the same certificate as the 3rd party certificate or a different certificate? If it's different - How do I get this fixed? Event Type: Warning Event Source: MSExchangeTransport Event Category: TransportService Event ID: 12018 Date: 9/24/2010 Time: 12:47:52 PM User: N/A Computer: XXXX Description: The STARTTLS certificate will expire soon: subject: XXXX.XXXX.net, hours remaining: FFA7EECE28EB07237760786BFB3472A770083586. Run the New-ExchangeCertificate cmdlet to create a new certificate. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.NC Beach Bum

New-ExchangeCertificate will generate a new self-signed certificate that is applied to SMTP. Simply run that command and say yes to replace. You can verify which cert its using with get-ExchangeCertificate and compare the thumbprint: FFA7EECE28EB07237760786BFB3472A77008358

Thanks very much! NC Beach Bum

Andy - Could this issue have something to do with my SMTP / POP users not being able to send / receive in Outlook? When I run the command get-exchangecertificate what I see are 4 certificates. Two of the certificates look to be for the same thing. Then I have two other certificates for with cn=mail.xxxxx.xxx and one for CN=www.owa.xxxxx.xxx 64FBB3445FC9780A06E428907DF7511FE5EC4153 IP..S CN=WXYZ FFA7EECE28EB07237760786BFB3472A770083586 IP..S CN=WXYZ Could my send and receive error be caused by still showing the 64FBB3445FC9780A06E428907DF7511FE5EC4153 certificate entry? If so, how do I remove it? NC Beach Bum

Did you verify what certificate is being used with SMTP? The self-signed or 3rd party? If you ran that command above and replaced the cert with the self-signed cert, and you need SMTP to be associated with the 3rd party cert, then use enable-exchangecertificate and associate the 3rd party cert with the SMTP instead.

Do a get-ExchangeCertificate | fl Then carefully look at each cert returned. Which ones are enabled for SMTP and are also valid? When did these errors start and what exactly are they?