Using Google Apps Standard - Emails being marked as spam

I signed up with Google apps standard edition for one of my domain names say example.com. I setup the emails like contact@example.com - and using the Google Email client and loggin as user contact - if I send emails to users - they arrive in their inbox.

But when I send it through my php script running on my hosting account where I have 开发者_运维百科registered the domain example.com - using the same email address contact@example.com - it ends up in the Spam folder - I've noticed this in both yahoo and gmail accounts

Any tips on how to prevent this from happening. Thanks

Does the computer you are sending the email from have a reverse PTR record? Jeff has a great post up today detailing the necessity of having one.

Another option is to just use one of the cloud based email providers. Some suggestions:

• http://postmarkapp.com
• http://www.socketlabs.com

Also make sure that the IP address you are using for email hasn't been black listed: http://www.mxtoolbox.com/blacklists.aspx.