Here's the current status of BIMI Support from the top 3 B2C US mailbox providers:
- Microsoft, no.
- Verizon, yes, beta.
- Gmail no, but...
Microsoft Outlook.com (Hotmail). Microsoft has not announced any support for BIMI. A competing system called "brand cards" has possibly been abandoned; multiple folks have told me that they have been unable to get enough information on how to implement a "brand card." There's no opportunity here until something changes.
Verizon Media. Covers AOL, Yahoo and Verizon domains. The webmail engine is still generally referred to as Yahoo Mail. Yahoo Mail does have support for BIMI. I believe this support to still be in beta mode. You can publish a BIMI record, but you must send "enough" mail for the Yahoo systems to notice a sender and attempt to look for and utilize a BIMI record. There is no formal submission process at this time. If you don't send many thousands of email messages to Yahoo, AOL and Verizon, then I wouldn't expect Yahoo Mail to notice and utilize your BIMI logo.
Gmail. Gmail has announced their intent to support BIMI, but has not indicated when that might launch. Meaning, there is no support at Gmail for BIMI today. If you want a logo to show next to email messages, this hack workaround still seems to work: Create a Google account for the email address you send from, and then upload your logo as the profile picture or avatar for that Google account. Within 24-36 hours, that image should now appear as your "BIMI-like" logo when sending to Gmail recipients. This appears to work when sending to Google Apps/Google for Business domains as well.
This means that if you send mail as email@example.com, you would create a new Google account "using your existing email address" and telling Google that your email address is firstname.lastname@example.org. Google will send a verification code via email to that address. You'll need to be able to receive that code and enter it back into the setup process in order to create this Google account. Then when fully created, navigate to "Manage your Google account" and click on the grey image circle at the top of the account management page to "select profile photo" and upload your logo image.
This seems to work as of April, 2020, but don't be too surprised if Google shuts this off at some point, or disconnects it from the Gmail logo display.
And finally, note that there is a mention of a "trust authority" in the BIMI spec, where the BIMI record can link to a certificate that validates that the use of a given logo is legitimate. (CNN appears to have gone through this process.) At this time, it is unclear if this is necessary or even recommended. One could interpret the spec to believe it to be required, but I don't think that's truly the case at this point. At some point, it is possible that an ISP, group of ISPs, or industry group may recommend or require use of this feature, but that has not happened yet.