I was able to solve this problem by setting up a relay on a remote and international vps, and then requiring an encrypted connection between that server to my h

I was able to solve this problem by setting up a relay on a remote and international vps, and then requiring an encrypted connection between that server to my home network. If the link was active, the mail would go through. If the link was inactive, it would queue up. That way I didn't need as reliable of a home network and could rely on the datacenter to maintain uptime. For a couple more dollars you could get a second VPS for even better uptime.