Microsoft 365 from GoDaddy Help

Fix rejected email with a bounce error

If you send an email and it can't be delivered to your recipient, it bounces back with an error message. If your email bounced back, search for the error message that you received to see its solution.

Note: These examples use the domain coolexample.com and the email address jane@coolexample.com — replace these with your own information.

Use Ctrl+F (or Command+F on a Mac) to search for your error's code, or select a bounce type to see a list of common errors and solutions.

Example: If your bounceback says, "552 Message rejected for spam or virus content," search for error code "552."

Recipient bounces

These are bouncebacks caused by issues with the recipient's email address or account.

Bounce errorCauseSolution
Account storage limitThe recipient's account has reached its storage limit and can't receive email right now. The recipient needs to delete messages from their inbox or the receiving folder to make space for more email.
Account does not existThe email address that you sent to does not exist.Verify that the recipient email address was entered correctly.
Account disabledThe recipient account exists but its ability to receive mail was disabled.Typically, these accounts remain permanently disabled, but you can try sending the email again later.
Delivery timeoutThis could happen for several reasons.Try again later.
This message is looping: it already has my Delivered-To line. (#5.4.6)The recipient account is forwarding the message in a loop.This is oftentimes because the receiver has two addresses that forward to each other. They need to correct their forwarding settings.

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Invalid recipient bounces

If the recipient email address is invalid or was misspelled, you might get these errors.

Bounce errorCauseSolution
550 Recipient not foundThe recipient is not a valid email address.Remove the invalid recipient from your email.
451 Sorry, I wasn’t able to establish an SMTP connection. I’m not going to try again; this message has been in the queue too long.

The recipient's email address has been misspelled or the recipient's email provider has blocked sending from your address.

Make sure the recipient's email address is valid and spelled correctly.

If you're sending to a group, you must reach out to each address individually to determine who is triggering the error.


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Sender bounces

These are bouncebacks caused by issues with the sender's email address or account.

Bounce errorCauseSolution
535 Authentication not allowed on IBSMTP Servers. IB401Authentication is not allowed on inbound mail. This happens when you have incorrect outgoing SMTP server settings set up in your email client, like Outlook or Gmail.Set up your email client using the SMTP server setting smtpout.secureserver.net.
550 jane@coolexample.com Blank From: addresses are not allowed. Provide a valid From. IB501The email message "from" field is blank.Add a valid "from" address and try to send the email again.
550 jane@coolexample.com IP addresses are not allowed as a From: Address. Provide a valid From. IB502Email messages can't be sent "from" an IP address.Add a valid "from" address and try to send the email again.
550 coolexample.com From: Domain is invalid. Provide a valid From: IB506The domain doesn't have valid MX Records, an IP address, or there were issues during the DNS lookup when the email was sent.Verify that you're sending from a valid domain. Then verify that the domain has valid DNS records by checking your zone file. If the DNS isn't valid, it must be fixed before you resend the email.
550 jane@coolexample.com Invalid SPF record. Inspect your SPF settings, and try again. IB508The sending email address's domain has an SPF record that does not authorize the sending email server to send email from the domain.Modify the SPF record to include the server you're trying to send from or remove the SPF record from the domain.
421 Temporarily rejected. Reverse DNS for this IP failed. IB108The IP address attempting to send mail does not have reverse DNS setup, or the DNS lookup failed.Verify the sending IP address has reverse DNS set up before resending the email. GoDaddy manages reverse DNS when using our email services. We do not support custom reverse DNS.

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Content bounces

If there are issues with the content in an email, you might get these errors.

Bounce errorCauseSolution
552 This message has been rejected due to content judged to be spam by the internet community. IB212The email message contains a link, attachment or pattern caught by our filters as spam.

Include an option to opt out in your messages.

Check your sending lists to ensure you're only sending to recipients who have selected to opt in to receiving your mail.

If you think the message was incorrectly flagged as spam, save a copy of the original message attempting to be sent, and then report the bounceback error.

Make sure any links in the email go to valid destinations that are free of malware and phishing scams.

552 Virus infected message rejected. IB705The email message containing a link, attachment or pattern caught by our filters as a possible virus.

Include an option to opt out in your messages.

Check your sending lists to ensure you're only sending to recipients who have selected to opt in to receiving your mail.

If you think the message was incorrectly flagged as spam, save a copy of the original message attempting to be sent, and then report the bounceback error.

Make sure any links in the email go to valid destinations that are free of malware and phishing scams.

552 Message rejected for spam or virus contentThe email message contains a link, attachment, or pattern caught by our filters as spam.

This error is caused by sending outbound email where the recipients did not request to receive email from you. We don't recommend sending outbound marketing email from our email platforms.

Make sure any links in the email go to valid destinations that are free of malware and phishing scams.


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Rate limiting bounces

You might get a rate limiting bounceback if there have been too many repeated actions in a certain timeframe.

Bounce errorCauseSolution
452 This message contains too many recipients. Reduce the number of recipients and retry. IB605The message has attempted to mail too many recipients.Reduce the number of recipients and try again.
421 Connection refused, too many sessions from This IP. Lower the number of concurrent sessions. IB007This IP address currently has too many sessions open.Check with your email provider to reduce the number of open sessions on your IP address and then try again.
421 Server temporarily unavailable. Try again later. IB101The email queue is experiencing higher than normal email volume.Try again later.
554 This IP has been temporarily blocked for attempting to send too many messages containing content judged to be spam by the Internet community. IB110This IP address has attempted to send too many messages containing content judged to be spam and has been blocked for an hour.If you're not sending spam, you'll need to contact your Internet Service Provider (ISP) to see why your IP address is sending so many emails. Something in your system is causing the issue, and you'll need to troubleshoot.
554 This IP has been blocked for the day, for attempting to send too many messages containing content judged to be spam by the Internet community. IB111This IP address has attempted to send too many messages containing content judged to be spam and has been blocked for the remainder of the day.Check the content of your message and try again later.
554 This IP has been temporarily blocked for attempting to mail too many invalid recipients. IB112This IP address has attempted to email too many invalid recipients and has been blocked for an hour.Check your recipient list and try again later.
554 This IP has been blocked for the day, for attempting to mail too many invalid recipients. IB113This IP address has attempted to email too many invalid recipients and has been blocked for the remainder of the day.Check your recipient list and try again later.
550 This IP has sent too many messages this hour. IB504This IP address has reached the maximum allowed messages for that hour.Try again later.
550 This message has exceeded the max number of messages per session. Open a new session and try again. IB510This IP address has reached the maximum allowed messages for that session.Try again later.
550 This IP has sent too many to too many recipients this hour. IB607This IP address has reached the maximum allowed recipients for that hour.Try again later.

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Remote block list (RBL) bounces

If the recipient is on a block list, you might get an RBL bounce.

Bounce errorCause Solution
554 RBL Reject.This IP address was blocked from our internal RBL.Use the link provided in the bounceback to submit a request to remove this IP address.
554 Connection refused. This IP has a poor reputation on Cloudmark Sender Intelligence (CSI). IB103This IP address has a poor reputation on Cloudmark Sender Intelligence (CSI).Use the link provided in the bounceback to check the reputation of the sending IP address in Cloudmark Sender Intelligence.
554 Connection refused. This IP address is listed on the Spamhaus Block List (SBL). IB104This IP address is listed on the Spamhaus Block List.Check to see if the IP address is listed on the Spamhaus Block List.
554 Connection refused. This IP address is listed on the Exploits Block List (XBL). IB105This IP address is listed on the Spamhaus Exploits Block List.Check to see if the IP address is listed on the Spamhaus Exploits Block List.
554 Connection refused. This IP address is listed on the Policy Block List (PBL). IB106This IP address is listed on the Spamhaus Policy Block List.Check to see if the IP address is listed on the Spamhaus Policy Block List.

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Microsoft 365 bounces

These are bouncebacks specific to Microsoft 365 email.

Bounce errorCauseSolution
5.1.1 RESOLVER.ADR. ExRecipNot Found; not foundThere are cached entries from the Nickname List or you deleted your Nickname Cache File.Try clearing cached entries from your Nickname list or deleting your Nickname Cache file. Learn more from Microsoft.
550 5.4.1 Recipient address rejected: Access denied. AS(201806281)The address is not recognized by the recipient system, such as email arriving at an incorrect server due to a DNS issue, or the recipient address isn't set up to receive email.Make sure you entered the correct email address. Verify the recipients' domain and MX records are properly configured for Microsoft 365. For more information, see this Microsoft article.
550 5.4.3118 Message expired, connection reset

50 4.4.318 Connection was closed abruptly
The receiving email server might be unwilling to accept the message because your domain isn’t authenticated.Enable and add DKIM to your domain’s DNS settings.
550 5.1.8 Access denied, bad outbound sender.Bad Outbound Sender - Messages sent from the Microsoft 365 email account may violate Microsoft's anti-spam policy. Check if the messages were intentionally sent by the email address, and then submit an unblock request.
550 5.7.705 Service unavailable. Access denied, tenant has exceeded threshold.Tenant Exceeded Threshold - Messages were sent from the Microsoft 365 organization that may violate Microsoft's anti-spam policy. Check if the messages were intentionally sent by the email address, and then contact a GoDaddy Guide for help unblocking the address.
Your organization does not allow external forwarding.By default, Microsoft doesn't allow forwarding to external email addresses.Edit your outbound spam filter policy.
550 5.7.708 Service unavailable. Access denied, traffic not accepted from this IPYou're sending from known, low reputation IP addresses. You might also have a new or trial version of Microsoft 365.Complete the appeal at sender.office.com or contact your Internet Service Provider (ISP) to do this.

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