When setting up Brand Indicators for Message Identification (BIMI), the 'selector' is a crucial component that provides flexibility and control. If you're familiar with DKIM, the concept will feel very similar. A BIMI selector is a simple label you choose, which becomes part of the DNS record's name. This allows a single domain to publish multiple BIMI records, each potentially pointing to a different logo.
The most common selector is simply named default. This creates a standard BIMI record at a location like default._bimi.yourdomain.com. However, the power of selectors comes from the ability to use other names, enabling you to manage different logos for various purposes, such as A/B testing or for different sub-brands, as the BIMI Group explains.
How BIMI selectors work
A BIMI selector is defined in your domain's DNS settings. It's the first part of the BIMI record's host name. For a standard setup, you would create a TXT record for default._bimi.yourdomain.com. Here, 'default' is the selector.
If you wanted to create a second BIMI record for a marketing campaign, you could choose a selector like 'marketing'. The corresponding DNS record would be hosted at marketing._bimi.yourdomain.com. When you send an email, you can specify which logo to use by including a BIMI-Selector header. If this header is omitted, receiving mail servers will look for the record with the 'default' selector.
Why use different BIMI selectors?
Using multiple selectors is an advanced BIMI strategy, but it unlocks some powerful branding opportunities. It's a feature designed for organizations that need more granular control over their brand's appearance in the inbox.
- Multiple Brands or Products: If you send email for different brands from the same domain, you can assign a unique logo to each one using distinct selectors.
- A/B Testing: You can test the performance of different logos. By sending a portion of your mail with one selector (and logo) and another portion with a different selector, you can measure engagement to see which visual resonates best with your audience.
- Seasonal or Campaign-Specific Logos: Use a special selector for a holiday campaign or a major event to display a temporary, themed logo without altering your main brand logo.
- Transactional vs. Marketing Emails: You could assign a simple, corporate logo for transactional messages (like password resets) and a more vibrant one for marketing communications.
How to create a BIMI record with a selector
Creating a BIMI record, whether it's the default or a custom one, follows the same process within your DNS provider.
First, choose a selector name. For your first record, this should be 'default'. For subsequent records, pick a descriptive name like 'marketing' or 'q1-promo'.
Next, navigate to your domain's DNS management panel and create a new TXT record. The host or name field will be selector._bimi (your DNS provider will automatically append your domain name). In the value field, you will add your BIMI assertion record, which looks something like this: v=BIMI1; l=https://your-cdn.com/logo.svg;
In summary, the selector for a BIMI record is the unique identifier that precedes ._bimi.yourdomain.com in your DNS. While 'default' is the standard and necessary starting point for most senders, using custom selectors offers a flexible way to manage your brand's visual identity across different email streams. It is an essential tool for any marketer looking to get the most out of their BIMI implementation.
