Here's another summary, basically a list of things to check/troubleshoot:
http://www.slipstick.com/problems/nosend.htm

So yes, the problem is well documented. The workaround/fixes are all out
there.

But the actual solution is so hard to find -- can someone explain?


Unsettled wrote:
I've run into this problem before, and it always seems to be some
magical thing like: move it out of the Outbox, close outlook, restart,
Send and receive, resend, and sometimes it works.

What exactly is the problem? I've suspected it has partly to do with
some sort of locking and how the PST works. As I understand, it's a
database for mail, calendar, and task data.

Is it some glitch in how the PST is? There are many in unix/linux
circles that will barf at the idea of storing mail in a database. Does
it all basically boil down to the mail store?