{"id":1373,"date":"2025-08-27T10:18:00","date_gmt":"2025-08-27T09:18:00","guid":{"rendered":"https:\/\/www.4uhosting.co.uk\/articles\/knowledgebase\/receiving-delivery-failures-for-messages-you-didn-t-send\/"},"modified":"2026-08-19T14:01:00","modified_gmt":"2026-08-19T13:01:00","slug":"receiving-delivery-failures-for-messages-you-didn-t-send","status":"publish","type":"kb_article","link":"https:\/\/www.4uhosting.co.uk\/articles\/knowledgebase\/receiving-delivery-failures-for-messages-you-didn-t-send\/","title":{"rendered":"Receiving Delivery Failures for Messages You Didn’t Send"},"content":{"rendered":"

If you receive delivery failure messages for emails you did not send, there are two common causes.<\/p>\n

Your mailbox may have been compromised, or a spammer may have spoofed your email address.<\/p>\n

Change the Mailbox Password<\/h2>\n

Change the mailbox password immediately.<\/p>\n

This is the safest first step because it stops anyone from logging in if the password has been compromised.<\/p>\n

Use a strong password that is not used anywhere else.<\/p>\n

Contact Support<\/h2>\n

Open a support ticket and tell us what has happened.<\/p>\n

We can check the server logs to see whether the messages were sent through your mailbox or whether your address was spoofed.<\/p>\n

If the Mailbox Was Compromised<\/h2>\n

If the mailbox was used to send spam:<\/p>\n

    \n
  1. Change the mailbox password.<\/li>\n
  2. Check for unknown forwarding rules or filters.<\/li>\n
  3. Scan any devices that access the mailbox.<\/li>\n
  4. Make sure the same password is not used anywhere else.<\/li>\n
  5. Contact us so we can check whether any further action is needed.<\/li>\n<\/ol>\n

    If the Address Was Spoofed<\/h2>\n

    Spoofing means a spammer sent email using your address as the fake return address.<\/p>\n

    In that case, the spam did not necessarily come from your mailbox or our server.<\/p>\n

    Unfortunately, you may still receive delivery failures because the failed messages are returned to the address shown in the email headers.<\/p>\n

    Why We Need the Headers<\/h2>\n

    The email headers help show where a message really came from.<\/p>\n

    If you contact support, include one of the delivery failure messages with the full headers if possible.<\/p>\n

    If you are not sure how to get the headers, send us the message you received and we will advise you.<\/p>\n","protected":false},"excerpt":{"rendered":"

    If you receive delivery failure messages for emails you did not send, there are two common causes. Your mailbox may have been compromised, or…<\/p>\n","protected":false},"author":1,"featured_media":0,"template":"","kb_category":[7],"class_list":["post-1373","kb_article","type-kb_article","status-publish","hentry","kb_category-email"],"_links":{"self":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article\/1373","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article"}],"about":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/types\/kb_article"}],"author":[{"embeddable":true,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":1,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article\/1373\/revisions"}],"predecessor-version":[{"id":2593,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_article\/1373\/revisions\/2593"}],"wp:attachment":[{"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/media?parent=1373"}],"wp:term":[{"taxonomy":"kb_category","embeddable":true,"href":"https:\/\/www.4uhosting.co.uk\/articles\/wp-json\/wp\/v2\/kb_category?post=1373"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}