Interesting.. I just got 1,100 inboxes with Inframail.. was using Gmail before (25 inboxes).. In my opinion, if the deliverability of Inframail or Inboxflow or Mailscale is 20% less, it'd still be worth it due to the fact that 1,100 inboxes would be $5,550 / mo., which is significantly more with all of these competitors.. One thing Inframail lacks is IP rotation though, so I'm considering other options in the future when I scale further.