We have Exchange 2003 on SBS 2003 32-bit 3.5GB of RAM (I know it is outdated but please spare me these kind of comments).
We have iPhones and Androids connecting to it to get emails. Weirdly, it works quite intermittently, for example: works on iPhone 6 iOS 8.2 but not on iPhone 5 iOS 8.2 and the same story with Androids. We tried removing and adding it so many times. During the removing and troubleshooting steps on iPhones I did the power + home buttons. We tried emails over wifi in the office and wifi outside as well as 3g in the office and outside of the office.
Our SBS certificate has expired recently so we renewed it on our SBS using the Internet Connection Wizard on SBS this has changed some of the permissions on the websites in IIS but I managed to change it and it started working.
The server doesn't seem under big load as the CPU is only few % in use and we have about 350MB RAM free and another 400MB in System Cache. We don't get any errors in the event viewer from Exchange regarding the performance.
We also have Blackberry server on SBS and while it alright and quick 95% of the time, occasionally we will get emails delayed.
There is over 25% free space on the server.
We have enough licences in the server 30 and it reports the maximum usage at 13.
We only have port 443 and port 25 open on our Draytek router which forwards straight to the server.
We have our PTR record in place.
However, we only have the forwarded port for our ActiveSync. We don't have autodiscover A record or the DNS SRV record but I am just about to create them.
I ran the Exchange Connectivity Test for ActiveSync (https://testconnectivity.microsoft.com
) and it fails not even being able to connect to OWA over my port 443 which is weird because I can go to that website.
I restored older firmware on the router to the point when we didn't experience any problems and I am able to telnet my server on port 443.
We will be moving to Office 365 within the next 3 months but it is then and my server doesn't work now.
Thank you for all your help.