My organization sometimes hosts distribution groups consisting of internal and external contacts. These groups accept messages from the outside so that members can email everyone in the group. As more organizations set up DMARC, will it cause these distro groups to not function properly. For example, we are organization A and the distro contains organizations B and C as well. If someone from organization C sends a message to the group and our server then tries to send the message along to organization B, will it get rejected because the envelope sender is from org C but it got sent to org B by my email server (org A). Sorry if my example is confusing.
I haven’t quite faced this issue, but I’m hoping others will chime if I do (and please correct me if I am wrong).
I think it depends on how things are setup with the distribution groups. If it’s being used to forward messages, similar to a listserv, then you would need ARC setup. However, if you are repackaging the message using the distro name, then you should be ok with the DMARC setup of the disto domain. Again, not 100% on that.
We use Google, so they use ARC on Google Groups, which we use as distribution groups.
Has anyone faced this situation?
Depending on the distribution group itself it may be possible to have the From: header updated and the message re-signed to make the message DMARC compliant Alternatively if the original message was DKIM signed, DKIM should survive forwarding and still pass DMARC with alignment.
The ARC standard should overcome some of the limitations DMARC has. The two most prominent use cases addressed are listservers and forwarding. While I am not sure this answers all of your question I think you have a use cases which would be covered