Outgoing mail shows in the headers:
Received-SPF: softfail (google.com: domain of transitioning firstname.lastname@example.org does not designate 22.214.171.124 as permitted sender) client-ip=126.96.36.199;
That means Google or other accepting mail server cannot get any positive authentication for this email, because there is no SPF record exists.
Create TXT record and add that specific IP (in our case 188.8.131.52) as a permitted sender.
The record will look something like this:
TXT domain.tld “v=spf1 ip4:184.108.40.206 ~all”