Hello, Recently I installed the Microsoft update MS12-006 (kb2585542) on a server running 2008 R2. After the installation we are having some issues with the server - specifically I cannot successfully telnet to the server. I can open a connection on Port 25 however after typing the helo command I get a "440 4.0.1 System Exception" error. Can anyone advise what the cause may be? Many Thanks.

Hi Ronan, Looking at what the hotfix entails, there's quite a lot of files being updated for the Server 2008 R2 platform - so much so that it's a little overwhelming trying to digest them all. Taking a step back and looking at the title, it leads me to ask if you have the TLS protocol enabled on the receive connector? There's two settings that this applies to: Transport Layer Security Basic Authentication -> Offer basic only after starting TLS So maybe there's something there to explore. What I'd say first and foremost is take a look at the application event log (and maybe even the system, but I'm not expecting anything here) on the Exchange host and look for errors there. That might shed a lot more light on the specifics of the system exception. Secondly, you could also try ensuring that the TLS security settings are disabled and then seeing if you can telnet in successfully. You may need to restart the Microsoft Exchange Transport beforehand just to ensure any currently loaded libraries are either not loaded or at least not being referenced as a dependancy. With this second option, the Transport service - in my experience, can take a heck of a long time to restart. Don't be alarmed if you get the timeout from the services mmc, just keep refreshing it every minute until it's stopped and manually start it again if this happens. If you run Forefront for Exchange, you're quite likely to see this. Just make sure you allocate up to five minutes for the restart and schedule a time where that won't upset folks. If you find any additional information from the event log, pop the details back here in the forum so the folks here can try and help out. Cheers, Lain

Hi Lain, Many thanks for your reply - this is not running Exchange, it is a 2008 R2 server running the IIS SMTP service. As far as I can see there is not many options related to enabling/disabling TLS. Cheers, Ronan

Hi Ronan, My apologies - serves me right for assuming. That being the case, have you tried removing then re-adding the SMTP Server feature? Assuming there's configuration changes you're worried about losing, you could achieve this by: From an elevated command prompt, run: c:\windows\system32\inetsrv\appcmd add backup smtpBackup-20120125 Remove the SMTP Server feature (reboot if required) Add the SMTP Server feature If required, from an elevated command prompt run: c:\windows\system32\inetsrv\appcmd restore backup smtpBackup-20120125 /stop:false If there's corrupt modules at play, this won't help. But if it's just some kind of bung class registration then it might just do the trick. Cheers, Lain