Likely due to the postfix configuration on server 2. I’d suggest that you configure it as a smart host or preferably use a SMTP plug in for your WP installation.
Thanks Alento. It’s Ruby on Rails. I’ll check these!
For better understanding, what do you think could be the issue in postfix config? Basically WP creates the mail but postfix doesn’t send it because it’s an address on the same domain?
Yeah … so really … you are going to have much less grief if you use a smtp plugin for WP. If you do not, you are going to need to create a custom SPF record as well as figuring out the issue in the first place.
Actually I already have a custom SPF, which I included in the Cloudflare DNS records. I modified the one for mydomain.com from
v=spf1 mx -all
to:
v=spf1 include:send.aweber.com mx a ip4:1.2.3.4 ip4:5.6.7.8 ip6:0000:1:2:3 mx -all
It solved the issue of having the notifications marked as “unsafe” by Gmail.
Actually this reminds me of an issue I had a couple of years ago with WP notifications on a VPS. Some loop due to postfix domain name config… (of course I don’t remember exactly what :-P). I’ll check the logs on both servers when I’m on the computer.