MX Records Simultaneous


We are transitioning to an infrastructure-as-code solution using Terraform. This solution is designed to enable the simultaneous ( rather than using priorities) sending of MX email messages to both Cloudflare and Duo Circle (email hosting service). You can find more details,

I’d appreciate any further guidance.


2 posts were merged into an existing topic: Requesting Help: Pointing MX Records to Cloudflare and Duo Circle


Check infrastructure-as-code solution using Terraform, Case Id. #3097195.


Um… what is it you are trying to do? That Terraform plan includes priorities for each of the MX records and it’s using both Cloudflare mail forwarding and another service which … even if possible would be terribly ill advised.

I intend to eliminate the MX priorities while ensuring that email messages are concurrently delivered to both Cloudflare Worker and Duo Circle (Mail Services). This objective can be achieved by utilizing a custom Terraform declaration. For more details, please refer to the following gist link:

Are you saying that if someone wants to send you email, that their mail service connect to two separate services at the same time, then deliver duplicate messages concurrently?

yes, this is true

No it can’t. That’s not how SMTP works.

1 Like

I know that’s why we are using Terraform’s declarations to build a custom email exchange,

The gist you posted clearly has MX record priorities and what you want to do simply is not possible… Terraform or not. That is not how SMTP works. A sending mail server picks a single server to send mail to. There is no option to simultaneously deliver to multiple mail servers in the relevant RFCs for SMTP.


I’ll refer to Google’s Cloud Architecture Center

This topic was automatically closed 3 days after the last reply. New replies are no longer allowed.