Most email clients have a way for users to “whitelist” a sender so
that messages from that sender aren’t filtered to the junk folder.

I investigated major email programs to find out what subscribers
should do, step by step, to ensure they see your messages:

In my last post, I brought up the topic of content filters and discussed what can be
done to minimize the chance of such filters affecting your messages.

Even when you do take those steps, however, it is still possible that a message
may be filtered. Today, I’ll provide guidelines for contacting an ISP about a
content filtering issue so that filter doesn’t continue to disrupt your mailings.

While ISPs still use IP blacklists to try to keep spam off of their systems,
they increasingly use other tactics to keep their users’ inboxes clear of
spam while still delivering requested messages. One comonly used
method is content filtering.

Microsoft has begun Sender ID look ups, displaying a large yellow alert box called a “safety bar” above messages that are not authenticated. Sender ID is the Microsoft implementation of the popular SPF authentication system which indicates which IP addresses a specific Sender or Return Path is permitted to send from. The safety bar will [...]