Getting spam complaints from your subscribers is the main reason for getting blacklisted.  Here are some things to you can do to prevent getting these complaints.

1.  Double opt-in – Having your subscriber’s double opt-in is not only a Email System policy, but is the best way to ensure the right people receiving your email blasts.  By having your subscribers confirm their subscription to your email blast you prevent any addresses from fraudulently being added to your lists.

2.  Control frequency of emails – If you haven’t sent to your list in a several months, some subscribers may forget that they had signed up, and complain.  You will want to keep in contact with them so they recognize your messages when they arrive in their inbox.

3.  Ensure You Have Valid Emails – ISP’s monitor how many soft and hard bounces occur during an email blast. Make sure that you have a clean list to start. This generally shouldn’t be a problem, but some clients have a double-optin list, but haven’t sent messages for a long time. In these cases you may wish to send slowly over time for your first couple of email blasts so that our system can clean your list without ISPs getting blacklisted.

4.  Don’t use subject lines that can appear to be spam – With spam being as big of a problem as it is these days, people sometimes assume a message is spam without getting past the subject line.  You will want to be sure to avoid terms that sound as though they could be used for spam (ex.  Don’t miss this free opportunity! / Great deals on new products!)

5.  Make sure your from name and address are familiar – If there is any confusion as to where your message is coming from, your subscribers would be much less inclined to report you as a spammer if they could contact you directly.

6.  Ensure opt-out URL is CLEARLY visible – Even if a subscriber has double-opted in to your mailing list, they may eventually decide they’d like to unsubscribe.  If you don’t give them the option to do so, their next step may very well be likely to report your message as spam.

If you have been blacklisted or want to request to be whitelisted with certain ISP please check out the link below with contact info fore the most commonly used ISP’s

http://www.Email System.com/kb/article.php?id=138