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?
Yes. I used to work for a very major cloud company and they resold sendgrid/twillo to folks wanting to send email. This happened after isps starting blocking port 25 to combat spam.
SendGrid is a very popular platform for programmatic email, as is the original Twilio for programmatic SMS. They have a very solid API and integrations, so are often a go-to for developers who want to offload the work of sending emails (account registration, notifications, password reset, order confirmation) and SMS (verification codes, etc).
Unfortunately Twilio (and thus SendGrid) is also used heavily for “marketing”, which in turn means they’re great for spammers too.
Still, I would never recommend IP blocking one of the largest programmatic email senders in the world. Inevitably your end users are going to miss something important, and while you may have saved them from hundreds of spam messages for every one important thing that they end up missing, we both know what they’re going to remember at the end of the day.
Edit: Realized I never answered your actual question. Here is a list of companies Twilio claims to provide email services for: https://customers.twilio.com/en-us/sendgrid
