Default values of DKIM and SPF records

We configured Exim to send mail through Maindrillapp.com for our server. We started using this to fix IP reputation issue that we had after an email sent SPAM without being detected. All emails sent by the server was being flagged as SPAM and all other solutions weren’t effective quickly.

In addition to changing the Exim config, Mandrill recommends adding SPF and DKIM keys for them. We did it for all the current domains hosted on the server and the delivery works great so far.

We are trying to find a way to get the SPF and DKIM custom Mandrill key implemented by default when creating an account. This way we won’t have to manually add and check that the values are there for new accounts.

The entries created in the DNS zone for the app looks like:

Key: mandrill._domainkey.domain.com
TTL : xx
value : v=DKIM1; k=rsa; p=xxxxxx;

and

Key : domain.com.
TTL : xx
value : v=spf1 +a +mx +ip4:xxx.xxx.xxx.xxx include:spf.mandrillapp.com ~all

How could this be implemented, is it possible to add these automatically on account creation?

Thanks