can’t quite remember what fixed this in the end - i just checked the host support tix for this - the last 2 things in our dialog that ended with email working were these:
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If your website is being hosted by others, please contact the concerned web host to change the e-mail routing to “REMOTE MAIL EXCHANGER”, not the “Automatically Detect Configuration: Local (recommended)”.
When you set it to REMOTE MAIL EXCHANGER”, your web server will recognize that all e-mail received in your domain sold be routed to remote mail exchanger to deliver to highest priority MX record.
When you choose the second option (Automatically Detect….), the your webs server takes responsibility to act as a main mail exchanger for all the mail s received in your domain address.
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and also:
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To create an SPF record for a domain:
1. Log in to the administrative console for your domain.
2. Locate the page from which you can update the DNS records.
You may need to enable advanced settings.
3. Create a TXT record containing this text: v=spf1 include:_spf.google.com ~all
Publishing an SPF record that uses -all instead of ~all may result in delivery problems. See Google IP address ranges for details about the addresses for the Google Apps mail servers.
4. If you use Google Message Security, you also need to include the Postini servers as authorized mail servers.
For details, see Configuring SPF for outbound services at the Postini Help Center.
5. Save your changes.
Keep in mind that changes to DNS records may take up to 48 hours to propagate throughout the Internet.
If you have difficulty creating an SPF record, contact your domain provider for assistance.
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