Hello @NickB439 ,
I'd strongly advise setting up self-authentication since you're sending using an address with your own, unique domain, and sending it internally - AKA to others within your domain. With all the delivery gatekeeping and anti-spam/malware safeguards in place, it's necessary for businesses using an ESP to have this in place.
If you're also needing to apply safelisting (or have your IT apply it), here's what the processes entail:
Safelisting domains in a security system
Safelisting email addresses in an email client or security system
If you're wanting more in-depth, specialized insight on your current deliverability, it'd be worth speaking with one of our Deliverability agents.
See also:
Email Authentication FAQ
... View more
