General Discussion
In reply to the discussion: In late Oct. 2016, remember how the NYT reported that the FBI saw no link between Trump and Russia? [View all]TheBlackAdder
(29,942 posts).
You have the polling between servers to maintain the connection or start the connection on-demand.
They don't need to perform an nslookup type command because they already have the IP address port and/or hostname/port and that would be even less plausible to perform a lookup if they were using a private leased-line or VPN between the sites.
The sending site would send an email and it would either fall into oblivion, get a negative or positive acknowledgement back from the email service running on the server.
It's been a while since I worked on email servers in my personal hosting sites and even longer with enterprise email servers.
But, if the FBI is thinking it could be spam or something, that means it's not an infrastructure or email services request.
Oh, and if you have a direct bank connection, you aren't getting spam.
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