Had a client pass on some information that may or may not come in handy for you. They had a problem with the Outlook 2007 Out of Office assistant when connected through the VPN. Out of Office worked fine when running Outlook while in the office. They checked name resolution, pinging all relevant servers using their FQDN with success. Their troubleshooting lead them to the patch below and after applying on their client workstations, the problem with the Out of Office assistant was resolved.
I had been using my MS Outlook for some years when I got my first PC. But for this time I had a lot of problems. And not always I could resolved theirs. To my good fortune I observed an unusual software on the I-net – ost pst converter. It settled my issues for a minute and I didn't spent the money.