Sent email in Outlook.com comes back "delivery failed"

When you send an email and receive a delivery failure message, there could be several reasons. We've listed the most common error messages below, along with suggested resolutions.

Select an error below to see more information.

Try this fix:    This type of error should fix itself over time. If your error message says that the recipient's email provider will keep trying to deliver your message, you don't need to take any further action. Otherwise, wait a short time and then resend the message.

Try this fix:    This type of error should fix itself over time. If your error message says that the recipient's email provider will keep trying to deliver your message, you don't need to take any further action. Otherwise, wait a short time and then resend the message.

Try this fix:   

  1. Review the email addresses that are shown in the error report. Are they correct?

  2. Remove any old/invalid email addresses from the group.

These terms are used when your message has been intentionally blocked by a spam or blacklist filter on the recipient's email server. The recipient's server believes that the mail server or mail account that you're using is a source of spam.

Try this fix:    You can contact the support team for the recipient's email provider and request to have your account or domain unblocked.

If you receive one of these messages, the domain for the recipient's email address doesn't exist. If their email address is someone@example.com, the domain is example.com.

Try this fix:    Check the recipient's email address for typos. Ensure you have the current address and that their email service provider hasn't made a change to their domain name.

This message means that the recipient has too many messages in their inbox. Many email systems prevent users from receiving any new mail until they reduce their mailbox size.

Try this fix:    If you have another way to contact the recipient, let them know that their mailbox is full.

If you receive one of these messages, the address you used doesn't exist. This could be because the recipient's address has changed or the recipient's email account has moved.

Try this fix:    Check the recipient's email address for typos. If you have another way to get in touch with the recipient, see if they have a new email address.

Often, this error message has the same cause as the Mailbox not found message. However, occasionally there's a problem with the recipient's email account that will resolve itself over time.

Try this fix:    Wait a short time and try to send your message again. If that fails, check the recipient's email address for typos. If you have another way to get in touch with the recipient, see if they have a new email address.

Most email service providers impose a limit on the size of messages their users can send or receive. Your message is too large for the recipient's email server.

Try this fix:    Instead of sending large attachments via email, upload them to OneDrive and send the recipient a link.

Try this fix:    This type of error should fix itself over time. If your error message says that the recipient's email provider will keep trying to deliver your message, you don't need to take any further action. Otherwise, wait a short time and then resend the message.

Try this fix:    This type of error should fix itself over time. If your error message says that the recipient's email provider will keep trying to deliver your message, you don't need to take any further action. Otherwise, wait a short time and then resend the message.

Try this fix:    This type of error should fix itself over time. If your error message says that the recipient's email provider will keep trying to deliver your message, you don't need to take any further action. Otherwise, wait a short time and then resend the message.

If you receive an error that a message is undeliverable, this could be due to the sending server trying to deliver the message, but the action didn't complete before the message expired. This error typically indicates a problem on the receiving server.

Try these fixes:    Make sure the recipient address is valid. Reduce the number of recipients in the message. If you received this error when sending a message using Outlook or another email app, try using Outlook.com to send the message instead.

Try this fix:    Check the recipient's email address for typos. Ensure you have the current address and that their email service provider hasn't made a change to their domain name.

Still need help?

Note: You will need to sign in first to get support. If you can't sign in, go to Account support.

Need more help?

Expand your Office skills
Explore training
Get new features first
Join Office Insiders

Was this information helpful?

×