Generally, the term "blacklist" means to exclude. Within the context of e-mail, "blacklisting" is a way to prevent e-mail from reaching its intended recipient(s). On a mass scale, this is sometimes achieved when an Internet Service Provider (ISP) "blacklists" all e-mail sent by a specific originator. Originators of mass e-mails are often blacklisted by ISPs due to spam concerns. Many ISPs and independent organizations will often use databases of blacklisted e-mail originators to filter inbound e-mail on their servers to aid in preventing spam and to encourage Internet security.

As defined by the Internet encyclopedia Wikipedia (

There is no universally accepted definition of spam, but most definitions are based on  the e-mail being both unsolicited by the recipients and having bulk quantities of substantively the same e-mail being sent. In other words spam is usually defined as Unsolicited Bulk E-mail (UBE). This e-mail is usually also unwanted and sent by automated means.

Unfortunately, legitimate businesses that generate significant volumes of e-mail can be blacklisted by a given ISP merely because they match certain criteria common with originators of spam.

Please note that spam (lowercase) should not be confused with SPAM (uppercase), the delicious luncheon meat produced by Hormel. For more information on SPAM, please visit

As a leader in the credit card processing industry, we send a very high volume of e-mail on a daily basis. For example, the majority of sales we process generate two e-mails, one to the consumer and one to the merchant. In 2005 we processed over 270 million transactions which translates into nearly 18 e-mails sent per second, every second of the day. Because some blacklist software look primarily at the rate and volume of e-mails, our valid e-mails are sometimes mistaken for spam. Additionally, merchants and their customers will sometimes mistakenly flag their e-mails from us as spam which increases our odds of being blacklisted.

Please be aware that Authorize.Net does not and never will send spam. We do not sell, rent, loan or share our clients' contact information with anyone.

Authorize.Net continuously works with industry leading ISPs to assure the delivery of our e-mails. Although we have had good success with most ISPs there are still several with which are working to recognize Authorize.Net as a legitimate and trustworthy originator of mass e-mail. Additionally, Authorize.Net has invested in hardware and software to more efficiently and intelligently manage e-mail delivery, which should help to reduce blacklisting. We continue to look for new technologies and solutions to further minimize the disruption caused by blacklisting.

There are several things you can do to help with this problem. It is important that you add the domain ("") to your approved senders list, or appropriately termed "whitelist" in your junk mail/spam filters. It is also very important you validate your e-mail address in the Merchant Interface. You can easily update your account information on your User Profile page in the Merchant Interface.

  • Step 1: Log into the Merchant Interface at
  • Step 2: Click User Profile in the main left side menu.
  • Step 3: Click Edit Profile Information.
  • Step 4: Update your First Name, Last Name, Title, Phone Number, Extension or Email Address(es) as necessary.
  • Step 5: Click Submit.

In addition, "bounced" e-mails that result when Authorize.Net sends communications to invalid addresses can compound the problem of being flagged as spam. If you do not wish to receive e-mails from Authorize.Net, you can help us avoid the problem of bounced e-mails by configuring as your e-mail address instead of an invalid e-mail address.

Finally, please take care not to flag an e-mail sent by Authorize.Net as spam. If you have concerns about the legitimacy of an e-mail that you have received from Atuhorize.Net, please contact Customer Support.

For further information, please see the Authorize.Net Spam policy.