@leroysflowers I am getting a lot of spam email from florist shops using an email that I only used once for you. Stop giving out email addresses or worse selling them. Thanks.
@HaloedPayload Or another case, where we started looking at other machines to see who had or didn't have the problem to help establish what was different, what changed.
@HaloedPayload Something that came to mind was working on a network performance problem. We had set traces but they weren't triggered. Decided to ask for a network diagram (should have earlier). When we got that, it was obvious there were multiple TCP/IP stacks and we had traced the wrong one.