Here's the current status of BIMI Support regarding the top B2C US mailbox providers:
- Verizon: Yes, supports BIMI.
- Microsoft: No support announced.
- Gmail: Support announced, likely to come in 2020.
- Just announced: Comcast, Fastmail and Seznam.cz.
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.
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.
Gmail. Gmail has announced their intent to support BIMI, and latest reports indicate that support may come in 2020.
Until that happens, there is no current support at Gmail for BIMI. 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 June, 2020, but don't be too surprised if Google shuts this off at some point, or disconnects it from the Gmail logo display.
Other ISPs: The BIMI working group has announced that three additional ISPs are planning on adding support for BIMI. Those ISPs are Comcast, Fastmail and Seznam.cz. Details to come.
In addition to noting that Microsoft has not announced plans to support BIMI, the BIMI working group update also lists ISPs 1&1 (Web.de/GMX/Mail.com) and Yahoo Japan as not having implemented or announced planned support for BIMI.