dmnelson, 
Our students are on Gmail. Staff are on-prem (for now.)
Barracuda adds an “external sender” warning to student mail, so I want to bypass it via an outbound gateway in Google. <https://support.google.com/a/answer/178333>
I can programmatically fetch Google’s netblocks from _spf.google.com
What's the best approach to keeping those up-to-date in Postfix or Sendmail list of permitted relay hosts?
I can kludge something together but wondering if anyone already did it and has a recommendation.
