Using the same From Domain for multiple Marketo instances

[rmoravick]

Hello!

I am working on a project where a client has two instances of Marketo and one is brand new and I am working on the admin set up tasks. They would like to use the same From Domain across both instances, example.company.com. My understanding is that this is not advised as an alias value is only allowed to appear once per DNS zone. Is my understanding correct? Would the best course of action be to have them establish a different domain for the new instance? Thank you.

[SanfordWhiteman · Accepted solution]

Using the same From: header domain is fine.

Has nothing to do with the alias (CNAME RR) limitation, as you don’t create any aliases for the From: domain. That’s only relevant to branding/tracking domains and LP domains.

You do need to get an alternate DKIM selector for one of the instances. That’s where there’s a possible DNS conflict. Marketo uses “m1” by default but the second instance can get “m2”. Open a support case on the “m2” instance to make that happen. 

[rmoravick]

Thank you for clarifying Sanford!

For the alternate DKIM selector, you are referring to the article here, correct? https://nation.marketo.com/t5/knowledgebase/dkim-conflict-when-two-marketo-instances-use-the-same-em...

In that case, I would open a support ticket to have them copy the verified DKIM key from the original instance and place it in the new instance so they both have the same DKIM key. Is that correct?

Thanks again!

[SanfordWhiteman]

No, you should ask for a different selector, m2.

You don't want the instances to be entangled by using the same selector (if you have to change one because of a compromise or any other reason, you don't want side effects).

[rmoravick]

Hey Sanford, 

Got it, thank you again!