Implementing DKIM with RT - Guidelines/recommendations?

This just popped up for me recently & I’m wondering how others are dealing with it:

I have an RT installation that is using various email domains for its queues. Ex: Queue A =, Queue B =, etc. Recently, we implemented DKIM and DMARC for our email to help shore up our online reputation. Everything was good. I then got a failure messages from Hotmail in regards to an email from RT. The mail went out as the Apache “mail address” with the “From”: header being one of the other domains and the signature failed. I’ve now turned on sending the mail out as the corresponder address, and bounce messages are coming back into the system now (I understand why this is happening).

Has anyone had any problems with a scenario like this with DKIM? What did you do to fix it?