I have found, in reviewing recent (Oct, Nov, Dec) emails that the bulk of announcements (some sales, some info, some confirmations) to which I subscribe are now being labelled [Shaw Suspected Junk Email]. These emails, or similar ones, e.g., ones with the same subject line, sender etc., would likely be sent to many recipients, thus likely triggering some spam threshold. Before October only the occasional such email was marked as spam. In other words the number of false positives among this type of email has increased dramatically.
Is there some reason for this seemingly more aggressive spam filtering? When it was just the occasional false positive, sending its headers to email@example.com wasn't a big deal but now it is becoming annoying. Does firstname.lastname@example.org even still work? In 2009 I received messages indicating that mail sent to email@example.com was undeliverable. Since then I have not received any indication, positive or negative, that email sent there has arrived, or not.
There are very few false positives among other types of emails, i.e. they are not being incorrectly marked as spam and there are relatively few false negatives, emails that are spam but weren't marked as such, so that is working well.
It seems that I had similar concerns in November of 2008.