Update: Gave them almost another week: no response, no acknowledgement, and no drop in spam. Fuck 'em. Banned both of their /16 CIDR ranges (159.183.0.0/16 and 149.72.0.0/16). None of their listed big users are any my org would be dealing with. If Sendgrid/Twilio had at least acknowledged a single one of the ~50 spam reports I sent over the course of 2 and a half weeks, I would have at least given them the benefit of the doubt.

I have been getting absolutely hammered with spam via SendGrid (Twilio), and it’s largely making it past the spam filters. I’ve trained on all of them, but they’re still not getting a high enough spam score for quarantine. I’ve lowered the score about as low a it can go without blocking legit mail (and most other spam is correctly caught).

This week alone, I’ve sent 8 abuse reports to abuse@sendgrid.net. Those plus the ones I sent last week have all gone unacknowledged and unanswered, and there has been no noticeable change in the inbound spam.

I’m to the point where I’m going to just IP block them entirely, but before I do, anyone know of any major companies I may inadvertently prevent from emailing me / my users?