Answered my own question. FYI we have a geoblock on our email as 99.9999999% of communications is from inside North America. It has helped cut down on spam a ton. Some reason the firewall is seeing the google servers for vehicleaccessorycenter.com as coming from outside US/Canada, hence the email is  getting blocked before it even gets to smarter mail.

How do you put a geo block on SmarterMail? I would so love to do this.

John,

 This is something that is setup at the firewall level. We subscribe to a service from Nuspire and they offer the ability to geo block for our email server. Outside of that I am not sure how they are technically doing it, probably have a list if IP addresses and originating countries and then they do a lookup as needed.

I know the original issue is now resolved, but I wanted to comment on the geoblock being mentioned. You can potentially set this up in Settings>Security>Blacklist. Here you'd simply enter a range that includes all IP addresses in a given country or location as a blacklist entry, preventing IP blocks from those locations from connecting. To ensure you don't block any traffic on a false positive basis, you can also implement a whitelist entry for your office IP addresses as we will check the whitelist before the blacklist. 

Thanks Kyle. I see I've used this area before. I will also talk to our Firewall vendor as well to do a block there as well.

You're very welcome John, happy to help! Be sure to add the range in CIDR notation here as it won't accept a hyphenated range. Have a good one!

Here's a site for getting IP Ranges or CIDR (per country). Be selective though as China has 13,000 rows. There is no import functionality and I would expect that many rows imported (or manually entered) would cause some serious slowdowns.

https://www.countryipblocks.net/acl.php