Send one message from Roundcube first
If Roundcube can send, the mailbox and UKC mail service are working and the problem is usually in the application or network. If Roundcube also fails, keep its exact error and contact us.
Mail application settings
Check the outgoing server
- SMTP server
- Your assigned UKC server, for example ukc12.uk
- Username
- Your complete mailbox email address
- Password
- Your mailbox password
- Authentication
- Required
- Preferred connection
- Port 465 with SSL / TLS
- Alternative connection
- Port 587 with STARTTLS
Do not use port 25 in a mail application. Many internet providers block it, and it is not the normal authenticated submission port.
Match the error
What the message usually tells you
- Authentication failed
- Check the full email address, reset the mailbox password and ensure SMTP authentication is enabled.
- Connection timed out or refused
- Check the server, port and encryption. Try another network to rule out a local firewall or provider block.
- Certificate warning
- Use the assigned UKC server hostname rather than mail.yourdomain or a raw IP address.
- Sender or relay denied
- Authenticate and use a From address permitted by that mailbox.
- Recipient rejected
- Test another recipient. The remote server may be rejecting the address, message or attachment.
WordPress and website forms
Use authenticated SMTP for website email
Configure the website or mail plugin with the same authenticated SMTP settings. Avoid relying on unauthenticated PHP mail. The From address should belong to the website's domain and be allowed by the authenticated mailbox.
What should I send UKC support?
Include the mailbox address, application name, UKC server, port, encryption type, date and time of the test, recipient domain and the complete error or bounce. Never include the mailbox password.
Request email help