"Message delivery to the host '74.125.25.[removed]' failed while delivering to the remote domain 'trans[removed].com' for the following reason: The remote server did not respond to a connection attempt."
"Message delivery to the host '173.194.79.[removed]' failed while delivering to the remote domain 'trans[removed].com' for the following reason: The connection was dropped by the remote host."
Free at present but I'm not convinced paid will make a difference in this case or any case.
Googling around for news - Google had 6 minutes of reduced Apps service affecting 10% of users on Wednesday recorded on status page and in the past there have been similar small outages now and then.
Mail disruption anywhere is not uncommon. Most mail servers seem to be configured for retry several times over a defined period (4 hours not unusual) to complete the delivery. I'm not sure to what extent a small outage or problem in the tubes is an issue for any normal email mail delivery.
My guess is geekzone notification mail is on a once only best attempt basis.