E-mails getting sent with unexpected sender- Mass Contact or Sendgrid fault?
- why does sendgrid override sender e-mail address
They give a reason why they might, but it doesn’t say they do: https://sendgrid.com/blog/dont-send-email-from-domains-you-dont-control/
There is the https://mc.sendgrid.com/senders option which seems like it might enforce who the actual sender is?
Or it might be a Mass contact bug.