A error message such as "The mail server responded ADMINISTRATIVE PROHIBITION. Please verify that your email address is correct in your Mail preferences and try again." or "550 Administrative prohibition" is due to the SMTP server blocking your attempt to send a message. Some typical causes:
- The domain used by your SMTP server is on one or more real time black lists (RBLs) and the recipients mail server is rejecting the message because a lot of spammers send mail from that domain. Try sending from another accounts SMTP server.
- The recipient is in a domain that is on one or more real time black lists (RBLs). Your email provider won't let you send the message since they suspect you're either replying to spam or have been compromised or hacked. Try sending using a different SMTP server.
- The SMTP server can't authenticate you. See 5.7.1_Unable_to_relay . If you're sending mail from a Gmail account try adding the Gmail SMTP server and using it.
- You're sending from a SMTP server with a dynamic IP address. Some ISPs mail servers reject messages sent from dynamic IP addresses. This might occur if you are using a local SMTP server (perhaps a built-in SMTP server in a webmail add-on or Free SMTP Server) and have a dynamic IP address due to using PPP, DHCP, PPPoA , PPPoE or a wireless connection. Try sending the message using your ISPs SMTP server.