Hello MarkV83, I hope you are well. If you are using your GoDaddy email with an Email Marketing Service to send out mass emails to many recipients, there may be an additional DNS setting called an SPF record that can resolve the issue. Contact your Email Marketing provider (IE, GoDaddy, Mail Chimp, Constant Contact, etc.) for this setting and enter into your domain's DNS. Here's some more information on SPF records:
*GoDaddy's SPF records are:
- Workspace: v=spf1 mx include:secureserver.net -all
- Office365: v=spf1 a mx ptr include:secureserver.net ~all
- cPanel: v=spf1 include:spf.protection.outlook.com -all
Also, you can use the link below to avoid spam filters based on the email content and recipient list as well as take a look at the CAN-SPAM Act guidelines.
Since there are various reasons why a message is recognized as SPAM, it's best to contact GoDaddy 24/7 support team so they can access your account, see specifically how you use your email and assist you further. Please note as well that if you are using any other email provider other than GoDaddy, you will want to contact their support for further assistance.