My Email Bounced Back — What Do I Do?
Understanding "Undelivered Mail" notices and how to fix the most common causes.
If you sent a message and got an automatic reply saying it couldn't be delivered (often titled “Undelivered Mail Returned to Sender” or “Mail Delivery Failed”), this is called a bounce. The good news: the bounce message almost always tells us exactly what went wrong.
Step 1 — Read the Bounce Message
Scroll to the bottom of the bounce notice. You'll usually find a short technical line with an error code and a brief explanation. Here are the most common ones:
- "User unknown" / "No such user" / "Mailbox not found" — the recipient's email address doesn't exist, or you may have typed it incorrectly. Double-check the spelling.
- "Mailbox full" / "Quota exceeded" — the recipient's mailbox is full. This is on their end — you'll need to reach them another way to let them know.
- "Message rejected" / "Spam" / "Blocked" / references to a blocklist — the recipient's mail provider flagged the message. This can happen even for legitimate mail.
- "Relay access denied" / "Sending limit exceeded" — usually related to sending a message to a large number of recipients at once.
Step 2 — What To Do Next
- Confirm the recipient's address is correct and still active — ask them to confirm if you can.
- If it's a mailbox-full bounce, there's nothing to fix on our end — let the recipient know their mailbox needs attention.
- If it mentions spam, a blocklist, or a reputation block, forward the full bounce message to us. We'll check our sending reputation and, if needed, request delisting with the recipient's mail provider.
- If you were sending to a large number of recipients and hit a sending limit, let us know roughly how many — we can advise on splitting into multiple email sends.
Still Stuck?
Please forward the entire bounce message (including the technical details at the bottom) to info@savemyservice.com, along with:
- The intended recipient's email address
- The approximate date and time you sent the message
- Whether this happens with every message you send, or just this one
With that information, we can usually trace exactly what happened and get you a fix.