I recently changed from my ISPs SMTP-server, to sendgrid a SMTP relay, since my ISP was disabling my email access since I “wasn’t using it” (I just used it for SMTP for mailcow, never logged in to their webmail).
However, after doing this, normal emails I’m sending out works fine, from SoGo to another external email, but on one of my accounts I have setup auto-forwarding to another external account. It will just fail, with sendgrid rejecting it based on “550 Verified sender identity”
<m***@**bo.org>: host smtp.sendgrid.net[188.8.131.52] said: 550 The
from address does not match a verified Sender Identity. Mail cannot be sent
until this error is resolved. Visit blabla….
So, the email was sent to <email@example.com>, and in its Sogo-account I’ve setup auto-forward to <m@**bo.org>. Why does sendgrid think the .org-address is sending the email, when it’s the recipient?
If I take an email in Sogo, and just forwards it to the same .org-email manually, it works just fine, as the .no-address is correctly added to sendgrid.