Hi there everyone Got a strange problem with OWA. First, my config : Exchange 2003 SP2 on Windows 2003 SP1 ISA 2000 on Windows 2000 Server SP4 Now, my OWA had been working fine since I upgraded to Exchange 2003 sometime in late 2003. Then about a month ago, the certificate that I used expired. I was getting a message whenever I tried to access the site complaining about the certificate, so I went to the Exchange server and renewed the certificate from there and then the problem went away. It seemed strange that I didn't have to do anything on the ISA server, but things worked fine so I didn't' worry about it. Then last week the the whole thing stopped working. Now, I should say, I can access the site fine internally. Its only when I try and access it externally that things don't work. I don't even get the message about an invalid certificate. I just get nothing. IE thinks for a while and then just seems to go back to the page where you were, as if nothing had happened. So, seeing as I needed to apply SP1 to Windows 2003 server and SP2 to Exchange 2003 I went ahead and did that thinking it might shake some things up and make things work. Well, no luck. So next, I went to the Exchange server, and exported the renewed certifcate and imported it into ISA server, since on the ISA server it showed it as expired. That all seemed to work fine, but still no joy with the OWA externally. So, I'm stumped now and was hoping that somebody could point me in the right direction as to where to start looking for some clues as to whats wrong. I've looked in the event logs but I don't see anything indicating any kind of error there. I'm not sure which logs to check to see if the traffic is coming thru. Any help would be greatly appreciated, Thanks Nick