[Help Request] How do I generate/provide DKIM/SPF Records for multiple domains on VPS with iRedMail?

Hello r/linuxadmin

I originally posted in sysadmin but thought this might be a more accurate place to request help from gurus.

I'm not sure if this should be posted here, r/dns or somewhere else, so apologies if I chose incorrectly.

I have multiple domains hosted on an Ubuntu 10.04 VPS running apache and iRedMail.
I followed this guide, and can successfully show my generated DKIM keys for the two domains I need to send mail from.
"amavisd-new testkeys" displays:

m => invalid (public key: not available) 

I added the corresponding keys to my (namecheap) DNS records using TXT records and the format of:

v=DKIM1; p=MIGfMA0GC **~SNIP~** QAB 

screenshot

I have also tried creating an SPF record using this and testing it using Brandon Checketts email test but I get
DKIM Signature

This message does not contain a DKIM Signature 

and
pastebin of SPF result

I am clearly missing something, I just don't know what or where. Any help is greatly appreciated.
Thank you.