Emails being rejected

Question

Hello, I have recently sent a couple of emails that have been rejected by the receiving party.

How can I fix this issue?

Answer 1

Hi Cheryl Waid-Foxgord

I understand how concerning it can be when emails are suddenly rejected without a clear reason.

Have you already tried the Q&A Assist suggestions under your post? In addition, please try these:

Before we continue, just to confirm: Are you sending email from a personal Outlook.com or personal email account configured in Classic Outlook for Windows, and not a work/ school account?

Also, since emails can be rejected for several different reasons, the key detail we still need is the Non‑Delivery Report (NDR) generated after the rejection.

Rather than posting the entire message, please copy only:

• The error code (for example: “550”, “554”, etc.)
• One or two error lines describing the reason

In the meantime, if you’re using Outlook with an Outlook.com / Hotmail / Live personal account, please try to remove and re‑add the email account in Outlook

This refreshes the local configuration and reconnects Outlook to Microsoft’s servers.

1. In Outlook, go to “File” > “Account Settings” > “Account Settings”
2. Select your email account > click “Remove"
3. Restart Outlook
4. Add the account back via “Add Account” and sign in normally.

Please feel free to let me know how it goes. Thank you for your patience and understanding.

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Answer 2

Hello, Can you please share the bounce email? It contains important diagnostic data that helps shed some light of the root cause. Without that information, possibilities can be many. Feel free to redact personal information when you share.

Answer 3

When email is rejected, the key is to check the exact error text in the Non-Delivery Report (NDR) or bounce message. Common causes and fixes based on the provided information:

1. Check for relay/550/553 errors If the bounce message mentions codes like 550, 553, or phrases such as “Relaying Denied” or “relay prohibited”:

• Cause: The outgoing SMTP server does not recognize the sender as an authorized user to send to that recipient/domain.
• Fix:
  • In Outlook for Windows, open File → Account Settings → Account Settings → Change for the email account and confirm:
    • The Outgoing (SMTP) server name is correct for the email provider.
    • Log on to incoming mail server before sending mail or My outgoing server (SMTP) requires authentication is enabled (wording depends on provider).
  • If using an ISP or third‑party mail provider, verify the correct SMTP settings (server name, port, SSL, authentication) from that provider and update them in Outlook.

2. If the NDR mentions “blocked”, “blacklist”, or sites like spamcop/spamhaus

• Cause: The recipient’s server is treating the sending server/account as a spam source.
• Fix:
  • Review the bounce message for any listed blacklist or block reason.
  • Contact the recipient’s email provider support (or ask the recipient to do so) and request that the sending address or domain be unblocked.

3. If the error mentions connection issues or “can’t connect to remote server” / “connection timed out”

• Cause: Temporary network or server issue between Outlook.com/Outlook and the recipient’s server.
• Fix:
  • Wait a while and resend the message.
  • If the NDR says the recipient’s provider will keep trying, no action is needed; it should resolve automatically.

4. If the error mentions group delivery problems

• Cause: One or more invalid addresses in a group or distribution list.
• Fix:
  • Review the addresses listed in the error report.
  • Remove or correct any old or invalid addresses from the group, then resend.

If the rejection continues, copy the full error text from the bounce message and use it to determine which of the above scenarios applies, then adjust the Outlook account’s SMTP settings or work with the recipient’s provider as indicated.

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References:

• I receive a 550, 553, or relay-prohibited error when sending email messages
• Sent email in Outlook.com comes back "delivery failed"