If your email forwarding address will be the same as your Blackbaud NetCommunity domain and you are hosted by Blackbaud, click Chat with Support and reference this article.  and the Domain. A Customer Support Analyst will contact you and arrange for our DNS servers to create MX and SPF records for your domain. A copy of your zone file may be needed, in some cases. 
For domains that are unique from your website domain, additional steps are needed:
Create 2 NS records:
  1. The first NS record will specify our Primary DNS server, bbns.blackbaud.com.
  2. The second NS record will specify our Secondary DNS server, bbns2.blackbaud.com.

Configuring DNS records is not supported by Blackbaud, as different providers have unique means in updating DNS records. Please contact the appropriate software vendor or IT professional for assistance with this process or issue, which is beyond Blackbaud's scope of support.