Introduction

This article explains what to do if you sent a Zivver message, or a regular email that Zivver secured, and it did not reach the recipient.

Which situation matches yours?

What you’re seeing depends on when the problem occurred:

Note

• If you received a notification email before your message was sent, asking you to remove content — that’s not a delivery failure. See Remove blocking content to send your email.
• If you received a notification email before your message was sent, asking you to add a phone number or access code for a recipient — that’s not a delivery failure. See Add recipient verification details to send your email.
• If your message was sent and you later received a bounce message back, or you see a warning icon on the read receipt of the sent message — that’s a genuine delivery failure. Continue reading below.

What a bounce looks like

A bounce — also called a non-delivery report (NDR) — usually shows up as:

• A new email in your inbox from a mail system, often with a subject line like “Undelivered Mail Returned to Sender”.
• In the Zivver WebApp: Read receipt An orange envelope with an exclamation mark on the read receipt of the sent message. Click the icon to see which recipients did not receive the message. See Read receipt for more information.

A bounce means your message left Zivver but could not be delivered to the recipient’s mail server.

Common causes

You don’t need technical knowledge to check the most common cause first:

• A typo in the recipient’s email address. This is by far the most common cause. Check the part after the @ carefully — a single wrong character (for example, .n instead of .com) is enough to cause a bounce.
• The recipient’s mail server is temporarily unavailable. This is on the recipient’s side, not something you can fix yourself.
• A security setting on the recipient’s side is misconfigured or out of date, for example an expired certificate used for secure email. This also needs to be resolved by the recipient’s own IT department.

What to do

1. Check the recipient’s email address for typos.
2. If you find a typo, correct it and resend the message.

If the address is correct, contact the recipient through another channel (for example by phone, a plain email to their address — this sometimes gets through even when the Zivver-secured message didn’t —, a different email address, or Teams/Slack) and ask them to check the issue with their own IT department.

Tip

A bounce is almost always something only the recipient’s side can resolve. If your organization has the Proof of Delivery feature enabled, you can look up the exact delivery status of a specific message yourself. See Proof of Delivery/Receipt report overview.

If this keeps happening for the same domain or organization, forward the bounce email to your own IT support or Zivver administrator. They can investigate further or contact Zivver support on your behalf.

For administrators

If you’re the Zivver administrator following up on a bounce, the detailed technical diagnosis (DNS records, TLS/DANE/NTA 7516 certificate checks) is covered in:

• Bounce 5.0.0 Unable … diagnostic code
• Bounce 5.3.0 Unable … delivered; 5.3.0