This took me a while to figure out and it may help someone else avoid the problem. Approximately one month ago, after one of the updates, I stopped receiving all notices sent to gmail. These included available updates, voice mails, backup logs and other notifications. Using email debug, I determined that the gmail servers were rejecting the SMTP send as “unauthorized.” Neither gmail nor anything else I could find on-line provided an answer that worked.
Well, it turned out that one of the updates, probably to the SysAdmin Pro module, had lost the local time setting and everything was defaulting to GMT. Apparently, Google’s servers compare the IP address to the time zone as one means of determining whether email is being spoofed. As soon as I reset it back to the correct time zone, all my email starting coming through again.
Just thought I’d share this in case anyone else runs into this problem.