Can I send email from my website's domain and a subdomain at the same time?

[skcjad]

I would like to send emails from both the primary domain and a subdomain on the same website.

www.example.com 

www.em.example.com 

Is this possible? If I set up DNS records for "go2.em.example.com" will they null my existing set up for "go2.example.com"

[SanfordWhiteman · Accepted solution]

I edited your post to use proper example domains — please don’t use other people’s private domains. (example.* and *.example are officially standardized and will never be registered to a private company.)

Next, let’s avoid saying “DNS records” as that’s far too general and DNS is very easy to mess up if you don’t understand the different record types. Instead, say “DNS A record”, “DNS CNAME record”, and so on.

www.example.com  and www.em.example.com seem irrelevant here. It’s perhaps good to know those names are already taken, but unless you’re sending from username@www.example.com they’re not directly involved in mail sending/receiving.

You seem to be asking:

Q: Can I set up DNS MX records for go2.em.example.com without affecting the MX records for go2.example.com?

A: Yes. The MX records need not even point to the same mailservers, though in your case it sounds like they will.

Q: Can I set up a DNS DKIM TXT record for m1._domainkey.em.go2.example.com without affecting the DNS TXT record at m1._domainkey.go2.example.com?

A: Yes. The DKIM public keys will be different, i.e the contents of the TXT record, but there is no problem having both of these active. You get the DKIM public key from the Admin UI.

[skcjad]

Thanks. Further clarification to my question:

I currently have go2.em.example.com set up to send mail from an instance in Marketo (Instance A)

I need to temporarily send emails from two different instances in Marketo at the same time. To successfully send out emails from two instances, I wanted to use go2.example.com. If I set up the DNS TXT record atm1._domainkey.go2.example.com on a second Marketo instance (Instance B), will it break the setup on the first one (Instance A)?

Why? The second instance has a dedicated IP address, and we'd like to use it. However the original instance has several undocumented integrations, and our dev team needs more time to migrate them.

[SanfordWhiteman]

You cannot have 2 DKIM TXT records with the same selector, no. Only one m1._domainkey.go2.example.com may be in use at any time.

So you need to ask Marketo to allocate a new selector, for example m2.

[skcjad]

Thanks. Our dev team managed to fix the integration. Good since it seems plan B would not have worked.