After using Ad-Aware SE, and allowing all its findings to be processed (ie the cookies and other stuff were removed from my system), I found that that inadvertently removed a setting which prevented me from sending our emails. I restored the removed items and recovered. I wonder which of the hundred or so items which were temporarily removed, should not have been?
Emails were returned with the message "No transport provider was available for delivery to this recipient.", making me think that it is a vital Plusnet item that I'm looking for.
Any clues anyone?
I don't know the specific component that is causing you the problem but if no-one else comes up with a better solution this is how I would tackle it.
Run Ad-Aware SE and flag half of the nasties if finds for removal.
If you find your system fails to send emails correctly you now know to problem is in the first fify nasties
Restore the components and repeat with the first 25 to be removed
Each time you halve the number of components to be tested
It will take a while but if no-one has a better idea........................