The problem is,
1. Your web application’s domain name is www.foo.com
2. Your server IP is 123.123.123.123, and it sends emails to users from support@foo.com
3. When a user danni@gmail.com gets an email from it, GMAIL may consider it is spam because it doesn’t know whether 123.123.123.123 really represents support@foo.com .
What you need to do is to setup a SPF DNS record for your domain, to tell people that 123.123.123.123 can send emails from xxx@foo.com. On Godaddy, you can do this according to,