- Permission

Confirming that people who ask for your information have actually requested to be on your list is number one step in battle for deliverability. You should be using a process called confirmed opt-in or verified opt-in to send a unique link to attempted subscriber when they request information. Before adding person to your list they must click that unique link verifying that they are indeed same person that owns email address and requested to subscribe.

- Subscriber Addresses

When requesting website visitors to opt-in ask for their "real" or "primary" email address instead of a free email address like Yahoo or Hotmail. Free emails tend to be throw away accounts and typically have a shorter lifetime than a primary ISP address.

- List Maintenance

Always promptly remove undeliverable addresses that bounce when sending email to them. An address that bounces with a permanent error 2-3 times in a 30 day period should be removed from list. ISP's track what percentage of your newsletters bounce and will block them if you attempt to continually deliver messages to closed subscriber mailboxes.

- Message Format

Usage of HTML messages to allow for text formatting, multiple columns, images, and brand recognition is growing in popularity and is widely supported by most email client software. Most spam is also HTML formatted and thus differentiating between requested email and spam HTML messages can be difficult. A 2004 study by AWeber.com shows that plain text messages are undeliverable 1.15% of time and HTML only messages were undeliverable 2.3%. If sending HTML it is important to always send a plain text alternative message, also called text/HTML multi-part mime format.

- Content

Many ISP's filter based on content that appears within message text.

E-mails now have a connection back to their servers. I will leave technical aspects out of this article. Instead, I will walk you through how information from your computer is getting back to them.

You have probably experienced this already, an e-mail lands in your box with many symbols in subject line created with Shift Key plus a Number Key. This is most common one. For example, it may look like this: &*)(*&^%$! Except length of symbols are longer.

When you click on it to delete it, any further action, including deletion of e-mail seems to go into la-la land. In other words, you can do anything else. This may last up to a minute or two depending on your computer speed. You have just been pinged and information is going back to their server saying there is a live connection.

In addition, because symbols change all time, it’s difficult to block them unless you use a program like Spam Arrest.

Here is an easy way and excellent way to protect from this and all you have to do is change way you dial in and out.