lucy24 - 5:26 am on Feb 28, 2013 (gmt 0)
If you figure out an e-mail code that says "I am not spam and I am exempt from all filtering", there are lots of people hereabouts that would pay you big money for it ;)
The problem is that spam filters by their very nature happen at the recipient's end. That's why account information even from Big Name Companies includes a blurb about "If you don't get it within five minutes, check your junk-mail box".
Where is the mail getting stuck? There are three places.
#1 the easy one: the user's local spam filter
#2 the ISP's optional pre-filtering. The user may or may not be able to turn this off, and they may or may not be able to use something like webmail to find any intercepted mailings. As when my current ISP decided to classify its own, individually requested mailings as spam.
#3 the ISP's absolute filter. Remember cyberpromo? You can bet that no self-respecting ISP accepted mail from this sender-- not even to put it straight into the recipients' spam boxes. If you're getting filtered at this level, all you can do is talk to the ISP. They may or may not listen.