What is whitelisting? In the email marketing world, the term is used to describe two main levels of deliverability: 1) At the ISP level and 2) At the user level. To simplify it a bit, whitelisting is essentially the opposite of blacklisting or confirmed spam. Now, why is it important? Whitelisting provides an additional opportunity to hit the end user's inbox. Is it failsafe? No, but really, what is in deliverability? A sender can get whitelisted if they are labeled as a safe sender by the subscriber and their ISP. Marketers will want to contact the major ISPs to determine if they have a whitelist set up and if they can be added. Bronto's IPs, for instance, are whitelisted at all major ISPs. This post will focus on the second inbox placement opportunity: Whitelisting by the end user. By whitelisting your address, a subscriber is saying "I've determined that your content is valuable enough for me to make sure I receive it in my inbox." It also means that your images are more likely to be displayed as the default versus images off. There are several opportunities, especially at the start of an email relationship, to push subscribers to whitelist. This includes on the sign-up form and thank you page, in the welcome message, in the preheader and so on. For tips and advice on how to get subscribers to whitelist through these traditional means, please see this post. Now let's explore where a few additional, potentially out of the box, opportunities to encourage whitelisting.


In some major ISPs, an email address is automatically added or saved to a user's contact list if the user has emailed that address. (It varies by number of replies as well.) That means that as a sender, you can – and should – be encouraging subscribers to reply to your messages. You can do this through a contest or promotion that pushes the reply (e.g., If you're Disney, you could do something like: "The first 50 subscribers to reply with their biggest wish are entered to win a trip to Disney!"). ISPs also factor replies into the new engagement-based deliverability metric, making it that much more of an incentive to ask. The caveat here is that you should use one reply-to address for all of your marketing messages, and potentially your transactional messages as well. Please don't make it a "do not reply" and contradict the purpose of your email. If you're asking subscribers to reply, you should monitor the address and do the same.


Consider including instructions for how to whitelist on or next to your sign-up form. Smartphone users can sync their contacts with their email client's list, so there's an opportunity to request that subscribers add your address to their mobile contacts list (perhaps with the local store number and location as well).


This is a tough one as whitelisting is near to impossible to measure. Really, the only tools you have to measure are your deliverability and inbox placement numbers and engagement metrics, but it's not a direct correlation. But think outside the box here: Could you have subscribers take a screenshot of your email address in their contact list? Will many subscribers do this? Probably not, but it might be worth trying.

Out of Stock Product Pages

When products are out of stock, it's a best practice to have potential customers sign up for back-in-stock alerts to secure a better chance of the conversion. What if you included your whitelisting instructions on these pages as well?

Social networks

Leverage multichannel synergy by incorporating sign-ups for marketing messages on your social profiles and vice versa. Right on the email sign-up callout, consider adding whitelisting instructions while you're top of mind. Social networks provide some intriguing emerging opportunities for email marketers. Whitelisting, if taken from a marketing channel holistic view, may need to be modified to "In Network." Whitelisting on social sites ensures that your brand is within the trusted circle of customers and brand advocates. It gives you more visibility, trust and engagement with your customers.

Emerging opportunities to become "In Network"

  • Google Buzz - Recently launched, there's been a lot of buzz about Buzz and the impact on email marketing. Very similar to an end user following your brand on Twitter or becoming a fan on Facebook, Buzz allows Gmail users to receive a feed showing activity by their contacts. This could mean that your emails, Tweets, YouTube feeds and blog posts make it to the top of the pile and breaks out from the typical inbox clutter. The practicality and adoption of Buzz is still being determined, but it's worth exploring and testing a push around subscribers adding you to their contacts list.
  • Facebook's Project Titan - The marketing strategists here at Bronto recently discussed this new Facebook feature and what it means for email marketers. From a whitelisting perspective, Project Titan provides yet another avenue to put your brand front and center and break through the average inbox clutter. If you make it to the inner circle, you have ample opportunity to create brand advocates out of your Facebook fans.
  • Yahoo/Twitter partnership - Yahoo just announced a partnership with Twitter integrating Twitter with its global platform, including Facebook, very similar to Google Buzz. Getting on subscribers' networks and contacts list will once again allow you to rise to the top of the pile. Just don't forget to put content out there, talk, converse and share on these social sites so you remain top of mind.
Whitelisting shouldn't be viewed as just a deliverability must-have, it should also be viewed as an opportunity to become a trusted member of a subscriber's network.