SendGrid repeat bounce: address on the bounce suppression list

Symptom: dropped events with reason 'Bounced Address' for a recipient you keep trying to mail.

Cause: the address hard-bounced, bounced a second time, and was logged to the bounce suppression list. Every further send is suppressed before it leaves SendGrid.

Confirmation: look the address up in Suppressions > Bounces in the console. If it is listed, that is the whole story.

Fix:

1. Find out why it bounced: typo, deactivated mailbox, or a dead domain. A suppression entry usually carries the original bounce reason.
2. If the address was fixed (typo corrected, mailbox reactivated), remove it from the bounce suppression list, then resend.
3. If the address is genuinely dead, remove it from your mailing list instead. Mailing dead addresses is what built the suppression entry.
4. Never bulk-delete the bounce list to 'fix' delivery. The list is protecting your reputation.

Verification: after removal, the next send produces processed/delivered events instead of a dropped event.

The bounces doc: a repeat bounce happens when an address bounced, bounced again, was logged to the bounce suppression list, and you asked Twilio to send to it again; Twilio suppresses the message because the address is recorded as invalid. Dropped events with reason 'Bounced Address' are the webhook signal. Sources: https://docs.sendgrid.com/ui/sending-email/bounces | https://docs.sendgrid.com/for-developers/tracking-events/event