I'm considering moving some clients to Google Apps Email and I'm concerned about potential email downtime. Assume that the domain is hosted on a VPS, and the MX records pointing to Google are also setup on the VPS.
A selling point for Google Apps is the separation of email services from potential downtime of the website on the VPS (all downtime is bad but email downtime IMHO is worse than website downtime).
If the VPS containing the MX records for each domain (set in cPanel for each individual domain) were to go down, would Google Apps Email also go down because the MX records -- on the VPS -- would not be available?
Is there some caching of MX records?