Error: MAIL FROM/RCPT TO/DATA not accepted from server!

Problem

Your email provider has SPF policy (Sender Policy Framework) verifying the FROM address and other mail parameters. With SPF policy, you cannot put anything you want in the FROM field, it needs to match your account address or at least your email domain.

Solution

Contact your host to solve this.

timeout

One more possible reason for the "DATA Not accepted from server" issue is too short timeout in communication between your server and mail server (SMTP as well). If answer not received in time this will also cause an error in your log