Wednesday, March 21, 2007

Exchange and Patches equals much confusion

We had installed some patches last month on our Exchange 2003 server that had some undesired effects, and also mislead me when trying to fix another problem.

The issue with the patches was all to do with shared mailbox access. We have a number of sales teams that all share one email account. The idea being that if a couple of members are on holiday on a call etc, then rest of the team can still pick up the emails.

The new patches (i'm not sure exactly witch one) tightened up some of the security settings, and meant that any users who used the shared mailbox and did not have there own individual mail account were unable to send mail. They kept getting errors like 'Resource not found', and 'You don't have permission to send on behalf of this user'

The way round it was to create mailbox's for these people, but hide them in the global address list so they see no difference. Looks like Microsoft implemented this to crack down on people using Exchange without a valid CAL.(note to self, setup a mirror of all our system in order to test all patches!!)

At the same time this happened, we also started to get errors from a couple of our users when sending email out using SMTP in an application we wrote. There didn't seam to be any pattern as to what was happening as some people saw no problems. The error was:
'550 5.7.1 Cannot Relay for

After much head scratching I finally realized that we had moved a couple of our terminal servers to our new subnet, and a quick check in Exchange system manager revealed that those subnets indeed weren't allowed to relay through the mail server. How easily we think something is a bigger problem than it actually is!

On another note I have had a play around with Flickr, the photo sharing site. I have to say i'm very impressed with what it can do. You can check out my one and only photo (so far) here The most impressive aspect of it is the Geotagging, that lets you give a co-ordinate to where the pics were taken, then view them in Google earth or other mapping systems.

All I need now is a digital camera with a GPS device and i'm set!

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