Swedish ISP Loopia offers free email forwarding for any domain for which they handle DNS.  Unfortunately, this includes a spam filter that the customer cannot turn off, unless they pay, which means it’s not free anymore.

So what’s wrong with some free spam filtering?  Well, this is what happened:

1. A prospective client sent an email with a proposition.
2. Loopia’s spam filter found the proposition suspect and bounced it.
3. The client saw a bounce and thought that they had the wrong email address and gave up.

This probably lead to lost business.  I can’t blame Loopia, but I can stop using them.