They're almost always short, and have Subject: lines that indicate what they're about, so it's easy to skip over them based on the Subject: line, and Gmail thinks I have 6.5GB of remaining quota space so it's not even worth the effort of deleting them. Sometimes they're even about issues like getting through the AOL email-rejection loop that are useful to multiple people. It's operational and de minimus.
Its operational and de minimus and sometimes the most simple way to arrange something... e.g. a mail filter/blackhole and no obvious contact phone number (e.g. the remote website is affected by the blackhole, etc). This is not a suggestion that NANOG should be carte-blanche a paging service, but in the few cases it appears, it doesn't seem to be clue-deprived requests that often. Deepak Jain AiNET