550 5.7.1 Relaying to <email@address.com> denied (authentication required)
Below are two options to look at in the Administration Console for a possible misconfigured setting.
- Verify the relay control settings within the Administration Console. Navigate to Configuration > SMTPSimple Mail Transport Protocol - An internet standard used for email transmission across IP networks. Server > Relay Control.
A brief description of each option:
- Users from IP Address Group.This option allows SMTP relaying if the traffic originates from an IP addressAn identifier assigned to devices connected to a TCP/IP network. contained within the selected IP Address Group.
- Users authenticated through SMTP for outgoing mail.This option requires the user's mail client to supply a user name and password for all the outgoing mail.
- Users previously authenticated through POP3Post Office Protocol 3 - A protocol used by local email clients to retrieve emails from mailboxes over a TCP/IP connection. from the same IP address (POP3 before SMTP). This option requires the user's mail client to check for new POP mail and authenticate before trying to send any outgoing messages.
- Verify the SMTP service has not been restricted to an IP Address Group.
- Navigate to Configuration > Services
- Double-click on the SMTP service
- Click on the Access tab
If an IP Address Group has been selected then disable that option, apply the change and then ask the user to try sending another email.