What is a SMIMEA record?

SMIMEA messages often contain a certificate (some messages contain more than one certificate). These certificates assist in authenticating the sender of the message and can be used for encrypting messages that will be sent in reply. In order for the SMIME receiver to authenticate that a message is from the sender identified in the message, the receiver's Mail User Agent (MUA) must validate that this certificate is associated with the purported sender. Currently, the MUA must trust a trust anchor upon which the sender's certificate is rooted and must successfully validate the certificate. There are other requirements on the MUA, such as associating the identity in the certificate with that of the message, that is out of scope for this document.

The SMIMEA record has the following look in your DNS zone management page:

Host Type Points to: TTL
www.domain.com SMIMEA 0 0 0 keyKEY1234keyKEY 1 Hour

How to create a DNS SMIMEA record?

Log in to your ClouDNS account, enter your DNS zone management page, and click on the Add new record button. For Type choose "SMIMEA" and type as follow:

  • Type: SMIMEA
  • TTL: 1 hour
  • Host: www
  • Usage: (From 0 to 3) It specifies the provided association that will be used to match the certificate presented in the TLS handshake
  • Selector: (From 0 to 1) It specifies which part of the TLS certificate presented by the server will be matched against the association data
  • Matching-type: (From 0 to 2) It specifies how the certificate association is presented.
  • Certificate: Specifies the "certificate association data" to be matched.

*This hostname is used as an example.

How to start managing SMIMEA records for your domain name?

  1. Create a free account from, here - free forever
  2. Verify your e-mail address
  3. Log into your control panel
  4. Create a new Master DNS from the [add new] button - check a tutorial, here
  5. Add the SMIMEA records you need, as it is described in this article.


Support of SMIMEA records

ClouDNS provides full support for SMIMEA records for all our DNS services, including the listed below. Just write to our technical support, if you need any assistance with your SMIMEA records configuration. Our Technical Support team is online for you 24/7 via live chat and tickets.

Last modified: 2022-01-11
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