Google apps not validating mx records
If this is your setup, then you will need to set up MX records on rackspace to point to rackspace mail servers, or point them back to godaddy to use their email servers.
COM/A/IN': .42#53 Sep 6 srv549 named: error (broken trust chain) resolving 'ALT2.
In terms of the settings, you will be using SSL for the Outgoing - this means that the email server URL should look like this secure##.(replace "##" with the server number for your server). When it's complete I'll post it as a response to this comment. Hi Joe, emails sent to you will be routed to where the MX records are set.
Deleting MX records If you deleted your MX records, email servers would not know where to deliver your email, so most likely you would have missed email sent to you in the time frame in question.
You might want to put some other dns entries in there too? Check that the mx records are pointing to rackspace and you should be good to go. If your Name Servers point to Godaddy and your A records point to Rackspace and you purchased the email hosting on godaddy (which it sounds like you did to set up forwarders) then you most likely have the MX records set to something like smtp.(godaddy's mail servers), which just sounds like a complete mess.
Now most people will typically point the NS to Rackspace, then they will manage the DNS on rackspace and have the email hosted on rackspace and then use fowarders in that email system to whatever address you want.