# What Is BIMI? Definition and Examples

> BIMI is an email specification that lets a domain publish its logo in DNS so supporting mailbox providers can show it next to authenticated messages.

Source: https://ssl.sh/glossary/bimi/
Last updated: 2026-11-10

BIMI (Brand Indicators for Message Identification) is an email specification developed by the AuthIndicators Working Group. A domain owner publishes a TXT record at `default._bimi.<domain>` pointing to an SVG logo and, usually, to a [Verified Mark Certificate](https://ssl.sh/glossary/vmc/). When a message passes DMARC, a supporting mailbox provider can fetch the logo and display it beside the message in the inbox.

## Why it matters
BIMI turns email authentication work into something visible: the logo is only eligible if the message passes DMARC and the domain enforces DMARC with a quarantine or reject policy. For brands, this gives recognizable inbox presence and an incentive to finish a DMARC rollout, which in turn makes spoofing the domain harder. Gmail, for example, requires the logo to be backed by a mark certificate such as a VMC before displaying it; the certificate is fetched as a [PEM](https://ssl.sh/glossary/pem/) file and validated like any other X.509 chain. Because each provider sets its own rules, the same domain may show a logo in one inbox and not in another.

## Example
```bash
dig +short TXT default._bimi.example.com
# "v=BIMI1; l=https://example.com/bimi/logo.svg; a=https://example.com/bimi/vmc.pem"
dig +short TXT _dmarc.example.com
# "v=DMARC1; p=reject; rua=mailto:dmarc@example.com"
```

## Common misconceptions
- **BIMI is an anti-spoofing protocol.** The protection comes from SPF, DKIM and DMARC; BIMI is a display layer that rewards having them in place.
- **Publishing the DNS record is enough.** Without DMARC enforcement, and usually a VMC, providers will not show the logo.
- **BIMI is related to S/MIME.** [S/MIME](https://ssl.sh/glossary/smime/) signs or encrypts individual messages with personal certificates; BIMI only governs how the sender's brand is displayed.

## Related terms

- [VMC](https://ssl.sh/zh/glossary/vmc/): VMC 是由 CA 核实组织拥有某个注册商标标志后签发的 X.509 证书，供邮箱服务通过 BIMI 显示发件人 Logo。
- [S/MIME](https://ssl.sh/zh/glossary/smime/): S/MIME 是一种使用 X.509 证书和 CMS 格式对电子邮件进行端到端签名和加密的标准。
- [STARTTLS](https://ssl.sh/zh/glossary/starttls/): STARTTLS 是一条协议命令，用于把 SMTP、IMAP、POP3 等协议中已建立的明文连接，在同一端口上升级为 TLS 加密连接。
- [PEM](https://ssl.sh/zh/glossary/pem/): PEM 是一种把 DER 二进制数据做 Base64 编码、再用 BEGIN 和 END 行包起来的文本格式，是存放证书和私钥最常见的方式。
- [X.509](https://ssl.sh/zh/glossary/x509/): X.509 是 ITU-T 制定的公钥证书标准格式，其互联网配置规范 RFC 5280 规定了 TLS 所用证书的结构和验证方法。