Perhaps surprisingly, I didn't handle your flags on either of those posts...
What I'm generally looking for in cases like this is whether the question is answerable.
Questions which present a configuration with a typo, for instance, are indeed answerable, and serve at least as a reminder to ensure that you're not making obvious mistakes. If you've been staring at your monitor for too long, you might well need that reminder. Plus, someone who pastes the typo into a Google search will have the opportunity to learn that it is in fact a typo.
I should also note that some typos are non-obvioussome typos are non-obvious and require a very careful eye to discern. When a single space can dramatically change the semantics of a configuration directive, it's very useful to have an explanation of what's going on.
On the other hand, if the question isn't answerable with the information provided, then it probably has no value to anyone other than the person who asked, even if he comes back and answers it himself. I don't usually see any problem with deleting such questions.
When the problem was caused by a typo and the typo was not presented, I'm probably going to hit the delete button, as such a question really isn't answerable.
I don't believe your example question of the exim TLS problem is a good example. After looking at the question, I think someone with sufficient experience with exim would have been able to make an educated guess at the cause of the problem. That the user answered his own question does not invalidate this, and as always, people are welcome to answer their own questions.
