There are a number of reasons why your Opt-Out Domain might be flagged by a Domain Blacklisting (DBL) Site.  The methods and tools used to identify a domain as being used 'incorrectly' can vary from one DBL site to another.  DBL sites also aren't necessarily forthcoming about their processes. However, below are some common reasons your Opt-Out Domain could be flagged by a DBL site.

- Spam Complaints: these are complaints made by email recipients who are receiving unwanted emails.  When these complaints meet a certain threshold, the email creative can be reported to or picked up by a DBL site.

- Spam Traps: many DBL sites will deploy this method to try and catch emailers sending to email addresses that have either not opted-in for communication or have unsubscribed.

- Bounces: this is usually a result of sending to a list of email addresses that have not been verified/validated, resulting in a higher than normal number of undeliverable emails that are then tracked as a "bounce".  After a certain amount of bounces, DBL sites may flag the domains used in the email.

- Non-Compliant Emails: this is usually driven by certain federal and state-level laws and regulations around what rules emailers must follow to legally send emails.  The main one being the CAN-SPAM Act in the U.S. When these rules are not followed, email domains are at risk of being blacklisted.

The above is not a comprehensive list but includes commonly recognized reasons behind a domain blacklisting.  Any time you find your domain on a DBL site, the site should tell you the reason it was flagged and give you the opportunity to dispute it.  Also, it is important to note that DBL sites will sometimes delist or remove domains from their lists without notice to the domain owner.  To find out more information about why DBL sites delist domains, please review this article: How do Blacklisted Domains get Delisted?

If you have further questions, please contact us at: support@optizmo.com