TODO: working with the blackboxes

https://www.m3aawg.org/sites/maawg/files/news/M3AAWG_Senders_BCP_Ver3-2015-02.pdf

No technical notes on "IP warming up". ESPs can come up with their own warm up policies. No BIG5 ESPs disclose their policies. So mailer services have to it the trial and error style, and the data obtained is kept as trade secret.

But I'm sure ESPs don't treat all the IP addresses equally. I'm pretty sure they whitelist all the government agencies and other big tech companies around the globe. Can't imagine Yahoo or Gmail getting complaints from Dept of Home Affairs or Internal Revenue Service. Also, there's a possibility of getting sued on the grounds of obstruction of correspondence.

Suddenly feeling huge respect for mobile network operators for their closed nature trying to get their shit together.