Like other email authentication standards, BIMI is essentially a text file. That text file follows a specific format and lives on your sending servers.
When a message is delivered, the recipient’s email service looks up the BIMI text file—and where it’s hosted—to ensure that the message can be verified. Once verified, the BIMI file tells the email service where to find the sender’s logo, and the email service pulls that logo into the inbox.
Although the underlying concept of BIMI sounds simple, there are a few key things to keep in mind when setting up BIMI for your own brand:
- You need additional authentication records set up for BIMI to work, including SPF, DKIM, and DMARC.
- You need to have access to your domain name servers to set up a new BIMI DNS entry.
- You must use an SVG file for your logo.
While only a few email clients support BIMI in their pilot program, other email clients will likely add BIMI support in the future. Depending on your ability to do the above, it may be a lot of work with limited payoff—at least for now.
Agari, part of the BIMI working group, put together a great post on how to get started with BIMI, including an example of what a typical BIMI text record looks like. If you really want to dig deep, you can check out the official BIMI working group’s Brand Indicators for Message Identification working draft, which goes into exceptional detail around how BIMI works for both senders and recipient mail transfer agents.
While BIMI promises more trust for subscribers and email senders, support is still limited. As of October 2020, the official BIMI adoption chart shows that:
- Yahoo!, AOL, Netscape, Fastmail, and Google are currently in the BIMI pilot.
- Comcast and Czech provider Seznam.cz are planning on support.
- And other email clients currently aren’t planning to support BIMI.
Like everything in email, BIMI support is likely to change over time. But, with major names like Google, Verizon Media, and Fastmail involved, it’s likely we’ll see more service providers joining the working group and pilot program over the coming years.