Brand Indicators for Message Identification, or BIMI (/ˈbɪmi/), is a specification allowing for the display of brand logos next to authenticated e-mails.
There are two parts to BIMI: a method for domain owners to publish the location of their indicators, and a means for mail transfer agents (MTAs) to verify the authenticity of the indicator.[1][2]
To implement BIMI, companies need a valid DMARC DNS record with a policy of either quarantine or reject, an exact square logo for the brand in SVG Tiny P/S format,[3] and a DNS TXT record for the domain indicating the URI location of the SVG file. The only supported transport for the SVG URI is HTTPS.[1] The BIMI DNS record is in the following format:
default._bimi TXT "v=BIMI1; l=https://example.com/image.svg; a=https://example.com/image/certificate.pem"
Additionally, services such as Gmail require that a Verified Mark Certificate (VMC) be acquired and presented with the TXT record in order for the brand logo to be displayed in the inbox.[4] These factors alone will not guarantee a BIMI logo will be displayed as heuristics (like spam and spoofing) and reputation will be a key part in BIMI validity.[5]
To query the value of the default._bimi
TXT record for a given domain, one can use the Dig command-line tool. For example, the following command will query the TXT record for the example.com domain: dig +short default._bimi.example.com TXT
.
A working group of several companies named "BIMI Group" has formed to develop and support standardization of BIMI in IETF.[6][7]
As of June 2023 the following e-mail services have implemented support for BIMI:[8]
Client | Requires VMC | Notes |
---|---|---|
AOL Mail | Unknown [9] | |
Apple Mail | Yes [10][11] | |
Fastmail | No [12][13] | |
Gmail | Yes [14][15] | |
La Poste | No [16] | Domains without VMCs must be submitted and manually verified by La Poste.[16] |
Yahoo! Mail | No [17] | Only for bulk emails from high reputation domains.[17] |
The BIMI Working Group was founded in 2019.[18]
The contributors of BIMI specifications, called the BIMI Group, also called Authindicators Working Group,[19][20] include: