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Likely fix

Fix: Email bounced back

A bounced email means the receiving mail server rejected the message or could not deliver it.

Quick answer

Read the bounce message for the reason, check the recipient address, remove large attachments, and try sending a simple message to one recipient.

Important warning

Bounce messages often contain the exact clue. Do not delete the bounce before reading the reason.

Try this

  1. 1 Open the bounce-back message.
  2. 2 Look for words like address not found, mailbox full, message too large, spam, SPF, DKIM, or DMARC.
  3. 3 Check the recipient address for typos.
  4. 4 Remove attachments and try a simple message.
  5. 5 Send to one recipient instead of many.
  6. 6 If the bounce mentions SPF, DKIM, or DMARC, check domain email settings.
  7. 7 If the bounce mentions spam or blocked, rewrite the message and avoid suspicious links or attachments.

Common causes

Wrong recipient address.

Recipient mailbox is full.

Message is too large.

Recipient server blocked the message.

Domain authentication problem.

Spam filter rejection.

What to check next

  • Check the exact bounce reason.
  • Check the recipient address.
  • Check whether the email has attachments.
  • Check whether the bounce mentions SPF, DKIM, or DMARC.
  • Check whether sending a simple test email works.

FAQ

What does email bounced back mean?

It means the message was not delivered and the receiving server or mail system sent it back with an error.

Where do I find the bounce reason?

Open the bounce-back email and look for the technical or plain-English reason, such as mailbox full, address not found, or message rejected.

Can SPF or DMARC cause bounced emails?

Yes. If your domain email authentication is wrong, receiving servers may reject your messages.

Related fixes

Fix: Email says address not found

Address not found usually means the recipient address is mistyped, no longer exists, has an old domain, or the recipient's mail server rejected it.

Fix: Email says recipient mailbox is full

Mailbox full means the recipient's email account has no space left or cannot accept new messages right now.

Fix: Email rejected because of SPF, DKIM, or DMARC

SPF, DKIM, and DMARC errors mean the receiving server could not verify that your email was allowed to send from your domain.

Fix: Email stuck in outbox

An email stuck in the outbox usually means the mail app cannot connect to the sending server, the attachment is too large, the app is offline, or the account needs you to sign in again.

Fix: Email won’t send with attachment

Emails with attachments fail when the file is too large, blocked by security rules, still uploading, stored only in the cloud, or using a file type the mail service refuses.

Fix: Website or domain email not sending

Domain email fails when DNS records, SMTP settings, website mail settings, SPF, DKIM, DMARC, or hosting mail limits are wrong.