There are two main types of subscribers you can acquire: single opt-in and double opt-in.

Single opt-in implies permission. Someone has given you explicit permission to send them an email in some capacity by entering their first name and email address and clicking on the submit button.

Double opt-in takes this process one step further. After the individual enters his first name and email address and clicks submit, he is sent a confirmation email. This email asks to click on a link to confirm that he does, in fact want to be subscribed to your newsletter. He only becomes a subscriber of your ezine or newsletter after clicking on that link.

I personally recommend acquiring only double opt-in subscribers as they are more valuable than single opt-in for three reasons.

One, the confirmation email gives the subscriber a chance to verify that he does want to receive your newsletter. His subscribing was not in error.

Two, the confirmation email makes it difficult for people to subscribe their buddies. For example, if Joe subscribes Bill to your newsletter and Bill receives a confirmation email, Bill can then choose whether or not he wants to be subscribed. In a single opt-in process, this would not happen and Bill could inadvertently be subscribed to your newsletter even though he didn't actually request to be on your list.

The third thing the confirmation email does is confirm that the entered email address is valid. The confirmation message is sent to the address the subscriber entered into the Web form on your subscription pages and he will not receive the message if the address is invalid. Therefore, you are not stuck with a bunch of 'dead' email addresses.

Your first email messages is often called the 'Thank You' message. To avoid being accused of spamming, use this messages to both thank your subscribers and tell them when and where they subscribed to your newsletter. This is also the all important courtesy letter and reminds subscribers that they did, in fact subscribe to your newsletter.

Another way of avoiding being accused of spamming is to include an unsubscribe link at the bottom of every message you send out. This is a link that subscribers can click on if they choose that they no longer want to be subscribed to your newsletter. Also, include your name and mailing address on the bottom of your email messages.

Increasingly, ISP's are using filtering systems to keep Spam out of inboxes and sometimes, they accidentally filter the email that you want to receive. To help alleviate this problem, you can ask your subscribers to place your emails and domains on their safe list and add them to their address books.

You should also spam-check your ezine messages. One way of doing this is to use the SiteSellSpamCheck Tool. The reply you will receive is a report telling you how good or bad your email is and what corrections you should make from a spam-detector's point of view.