What a 'Delivery Failed' status means and what to do

If a certified email shows Delivery Failed, it means the recipient's mail server did not accept the message when MailProof's relay tried to hand it over. No delivery took place, so no delivery is certified for that send.

Common reasons a delivery fails:

• The recipient's email address is mistyped or no longer exists.
• The recipient's mail server rejected or bounced the message (for example, a full mailbox or a server-side block).
• A temporary problem at the recipient's end.

What to do:

1. Check the address carefully for typos and re-confirm you have the right one.
2. Try again once you are confident the address is correct — a failure caused by a temporary problem at the recipient's server may clear.
3. If it keeps failing, the issue is almost certainly at the recipient's end; consider confirming the correct address with them through another channel.

Because a failed send was never delivered, it cannot be used as proof — only a delivered and confirmed message produces valid evidence. If a notice is deadline-sensitive, resolve the address problem promptly so a successful, certified delivery is recorded in time.