I have an exchange server 2010 running and have a bunch of users connected directly through Outlook and a bunch more using OWA to get their emails. It has been running solid for several years, but now I am getting random complaints from some users that they are able to send one or two emails and then get the following error:
Your network connection isn't available. If the problem continues, contact your helpdesk with this HTTP Status code: 12019.
Their network connections seem reasonably stable (they are able to use other online services without issue). This is with different users at different onsite and offsite (connecting via LAN and WAN) locations. The issue seems to be getting worse but not able to pin it down to one location, machine, OS or otherwise.
I have run the MS Exchange Troubleshooting Assistant and did not get any issues except that the EXMon tracing was not enabled, so I enabled it with the registry mods described in the help, restarted MSExchange Information Store services and ran it again. This time it did show that 98% of the CPU was utilized by 6 users, and with the exception of slightly slower disk access times than recommended, all looked OK.
I also checked the Exchange Server logs and the tool found 1 Failure Event for all processes (with no further description on the error) but only one error probably is not related.
Any other thoughts or ideas of things to check would be appreciated.