If I had a nickel for every time GoDaddy came up in this forum...
Connectivity test also reveals port 25 Outbound = Closed but shows service Available SMTP in green.
GoDaddy blocks all access between your website and external SMTP servers. The only available servers are the local ones (on GoDaddy's intranet): localhost and relay-hosting.secureserver.net.
Any solution at this point is fine with me.
I have a few ideas.
1. Everything is working perfectly but your domain SPF is misconfigured causing the receiving server to trash your email. Please read WordPress emails are sent but not received
dahlemail.com. 599 IN TXT "v=spf1 include:spf.protection.outlook.com -all"
outlook.com??? your sender is godaddy.
2. Make sure your email subject line is not blank. Try configuring Postman to use localhost instead of relay-hosting.secureserver.net. Try enabling "Remote MX".
3. Try configuring Postman with a Gmail address using the Gmail API. That works from GoDaddy since it uses the HTTPS port, not the SMTP ports.
