We recently bought our domain. It turns out, two generations ago, it was a porn site.
Now we're still blocked in some filters, resulting in blocked pages at several corporate routers.
I'm now sending mails out to some of those filters, but is there a general way of whitelisting?
No, there is no "global" list; every company maintains their own classifications. So you will have to contact each one individually.
Some black lists will drop you once you are again "Clean", but this depends on the list. Generally, if you are still blacklisted you will need to make contact; This has been my experience.
This site gives some good info. http://www.dummies.com/how-to/content/how-to-get-removed-from-an-email-blacklist.html
There are a couple of sites such as this one, but it all depends on if the receiving party implements this type of checking, not all do.
If your domain makes it to one of these lists, you'll have to contact that site typically to get removed, and it takes a little while. I don't know if they have a policy where the domain automatically drops off after a certain amount of time, it would all depends.
Also, remember that the Outlook client will use an internal list for it's own junk email filter, which is separate from even the corporate mail filtering in place, if any exists.
