BIMI, or Brand Indicators for Message Identification, is a new open industry standard for displaying your logo in users' mail clients, adding an extra layer of verification that the message being opened was sent by your organization.
With the BIMI standard just being recently released and still being worked on, there are a few limitations. At the current time of writing, only Yahoo supports displaying BIMI logos. The sending email address must send a sufficient amount of mail your users actually engage with. When looking to enable BIMI you should focus on those domains and senders first. One easy way to identify these is to use the Email Traffic Analyzer "What ISPs do I send to?" report. This will give the concrete volume of messages sent to Yahoo and ones most likely to be for B2C communication.