Troubleshoot a Cisco VPN

Good Cisco VPN troubleshooting checksheet
http://www.cisco.com/en/US/products/ps6120/products_tech_note09186a00807e0aca.shtml

Unauthenticated Relay in Exchange

This is primarily for Exchange 2007, but should work in newer versions also.

http://www.commodore.ca/windows/exchange/exchange_2007_unauthenticated_relay.htm

References:
http://www.commodore.ca/windows/exchange/exchange_2007_unauthenticated_relay.htm

Outlook Performance and Mailbox Size or Item Count

Mailbox size or item count can have a serious effect on the performance you see in Outlook. The following article gives some good insight into why, and what can be done about it.

http://blogs.technet.com/b/exchange/archive/2005/03/14/395229.aspx

References:
http://blogs.technet.com/b/exchange/archive/2005/03/14/395229.aspx