At the end of the day you have to take a stance, come up with a company policy and try your best to stick with it.

If you don't want false positives then you'll have to live with spam, unfortunately we don't live in an ideal world - if we did spam wouldn't be a problem.

Senders who are blocked for not having a reverse DNS I see as their problem. If they sent to me, or AOL they'd also get blocked. What is the common denominator? The sender!

I explain all this to my customers, I explain we arn't the only people who refuse these emails, and they will be blocked by more and more people as more introduce anti spam measures. It's therefore the senders problem, and in their best interests to sort things out. If they did their emails would get through fine.

I tell them its like sending a letter in the post without the correct postage, Royal Mail hold the letter in 'quarantine' and inform the recipient, who would then have to go to collect the letter, pay the correct postage + an administration charge. If that doesn't happen within x number of days, Royal Mail return the letter to the sender. I see no difference with email, senders have to follow equivalent practices to make sure their emails will be received, like using the post/zip code, paying the correct postage etc, with emails its 'have a correct MX' 'have a valid reverse DNS'.

As I said before I explain to my customers what the problem is, I turn them round to my way of thinking, and more often than not my customers do the same and manage to get the senders to adheare. But if not, they get whitelisted via the quarantine anyway.

There are obviously a small number of customers who are never happy, as they want to block spam without any false positives, and try to make it my problem to sort out. I don't accept this, I stand my ground, and when I don't budge they ask me to turn off the anti spam.

Unfortunately I don't want to do this either, as doing this means my server has to process unnessesary spam and undeliverable bounce backs. I explain to my customer that our anti spam measures are not only to improve the services they receive, but also to protect our servers so that we can providing a continuous and unhindered service to all our other customers, preventing us from being affected by spam attacks (which has happened in the past!).

So I say that if you don't want anti spam, we can point all your email directly to your server (via DNS) therefore bypassing our servers. However this means you will receive all spam, and also your emails will not be virus scanned by us. So far I don't think any customer faced with this option has actually taken me up on it. I think they just try to call my bluff to make their lives easier, as some humans think that if they shout loud enough they'll get what they want - maybe this is what happened when they were young children screaming and shouting at parents to get a new toy or some sweets, but not with me - I don't give in to this behaviour from my four children & boxer dog so why should I give in to the adult version?

Don't I sound harsh!?? :)

Regards,
Lyndon.