Why Won’t My Email Send?

These checks are for mailboxes hosted with us. The full list of server names and ports is on our email settings page.

1. Check the outgoing server name

The outgoing (SMTP) server should be smtp.interdns.co.uk. Phones and mail programs sometimes keep an old provider’s server, or fill in a guess of their own.

2. Make sure it signs in

Our servers only send email for customers who sign in, so the outgoing server needs a username and password: your full email address and your mailbox password, the same ones you use to receive. In Outlook this is the setting My outgoing server requires authentication.

3. Try a different port

The standard port is 25. Some broadband providers block port 25 for sending, so if email won’t go out, change the outgoing port to 587 or 2500.

4. Check the security setting

Turn on STARTTLS (recommended) or TLS for the outgoing server, so your password is sent encrypted. On an iPhone or iPad, turning on SSL changes the port number by itself: change it back to 25, 2500 or 587.

5. Changed your password?

If you have changed your mailbox password, update it on every phone, tablet and computer that sends from that address. A device still using the old password will keep failing until it’s updated.