With the multitude of VPNs out there including those bundled with some browsers, we don't make exceptions - a VPN solution with the exit node being in an approved country is the only way to go. If you are worried about getting a "dodgy" VPN, I suggest assembling a "recommended list" for your users when they are required to use one.
We use Windscribe due to multi-platform clients and ease of use, but that's neither here nor there (and not a paid endorsement) -
MailEnable survivor / convert --