{"id":221,"date":"2025-12-17T10:17:12","date_gmt":"2025-12-17T09:17:12","guid":{"rendered":"https:\/\/mybox.com\/help\/?post_type=manual_kb&#038;p=221"},"modified":"2026-06-14T23:47:49","modified_gmt":"2026-06-14T21:47:49","slug":"eroarea-550-in-e-mailuri-cauzeaza-mesaje-si-modalitati-de-rezolvare","status":"publish","type":"manual_kb","link":"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/","title":{"rendered":"Eroarea de e-mail 550: cauze, mesaje \u0219i solu\u021bii"},"content":{"rendered":"<div class=\"translation-block translation-block-merged\">\n<p class=\"wp-block-paragraph\">Error 550 is one of the most common email delivery errors. It indicates that the recipient&#8217;s mail server has rejected the message and refused delivery.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Unlike temporary delivery errors, a 550 error usually requires action before the message can be successfully delivered.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#What_Does_Error_550_Mean\" >What Does Error 550 Mean?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Common_Causes_of_Error_550\" >Common Causes of Error 550<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Invalid_Recipient_Address\" >Invalid Recipient Address<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Mailbox_Does_Not_Exist\" >Mailbox Does Not Exist<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Sender_Reputation_Issues\" >Sender Reputation Issues<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#SPF_DKIM_or_DMARC_Failures\" >SPF, DKIM or DMARC Failures<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Relay_Access_Denied\" >Relay Access Denied<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Spam_Detection\" >Spam Detection<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#How_to_Troubleshoot_Error_550\" >How to Troubleshoot Error 550<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#1_Review_the_Full_Error_Message\" >1. Review the Full Error Message<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#2_Verify_the_Recipient_Address\" >2. Verify the Recipient Address<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#3_Check_SPF_DKIM_and_DMARC_Records\" >3. Check SPF, DKIM and DMARC Records<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#4_Check_Server_Reputation\" >4. Check Server Reputation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#5_Contact_the_Recipient\" >5. Contact the Recipient<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Preventing_Error_550\" >Preventing Error 550<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/mybox.com\/help\/ro\/knowledgebase\/error-550-in-emails-causes-messages-and-ways-to-solve\/#Summary\" >Summary<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Does_Error_550_Mean\"><\/span>What Does Error 550 Mean?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<\/div>\n\n<div id=\"mybox-1650852553\" class=\"mybox-content mybox-entity-placement\"><div class=\"early-access-banner-inpost\">\r\n  <div class=\"banner-left-inpost\">\r\n    <div class=\"icon-box-inpost\">\r\n      <img decoding=\"async\" src=\"https:\/\/mybox.com\/help\/wp-content\/uploads\/2026\/02\/square-info-icon.svg\" alt=\"Info\">\r\n    <\/div>\r\n    <div class=\"text-box-inpost\">\r\n      <span class=\"label-inpost\"><span class=\"translation-block translation-block-banner-text\">Acces timpuriu<\/span><\/span>\r\n      <h4><span class=\"translation-block translation-block-banner-text\">Mai ave\u021bi nevoie de ajutor?<\/span><\/h4>\r\n      <p><span class=\"translation-block translation-block-banner-text\">Contacta\u021bi echipa noastr\u0103 de servicii pentru clien\u021bi.<\/span><\/p>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <div class=\"banner-right-inpost\">\r\n    <a href=\"https:\/\/panel.mybox.com\/helpdesk2\/v\/list\/\" class=\"banner-button-inpost\"><span class=\"translation-block translation-block-banner-text\">Trimite mesaj<\/span><\/a>\r\n  <\/div>\r\n<\/div><\/div>\n\n<div class=\"translation-block translation-block-merged\"><p class=\"wp-block-paragraph\">The SMTP code <strong>550<\/strong> is a permanent delivery failure returned by the recipient&#8217;s mail server. It typically means the server has determined that the message, sender, recipient, or server configuration does not meet its acceptance requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because the exact reason varies, the full error message should always be reviewed alongside the error code.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Common_Causes_of_Error_550\"><\/span>Common Causes of Error 550<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Invalid_Recipient_Address\"><\/span>Invalid Recipient Address<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">One of the most common reasons is that the recipient email address does not exist.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 User unknown\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Possible causes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Typographical error in the address<\/li>\n\n\n\n<li>Deleted mailbox<\/li>\n\n\n\n<li>Incorrect domain name<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Always verify that the recipient address is correct before attempting to resend the message.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Mailbox_Does_Not_Exist\"><\/span>Mailbox Does Not Exist<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The destination mail server may reject the message because the mailbox has never been created or has already been removed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 No such user here\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Sender_Reputation_Issues\"><\/span>Sender Reputation Issues<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Many mail providers reject messages originating from servers with a poor reputation or IP addresses listed on spam blacklists.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 Message rejected due to IP reputation\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">This commonly occurs when:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A server has previously sent spam<\/li>\n\n\n\n<li>A compromised website or mailbox has been abused for mass mailing<\/li>\n\n\n\n<li>The sending IP appears on a public blacklist<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"SPF_DKIM_or_DMARC_Failures\"><\/span>SPF, DKIM or DMARC Failures<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Modern mail servers verify sender authenticity using DNS-based email authentication mechanisms.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Examples:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 SPF check failed\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>550 DMARC policy reject\n<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>550 DKIM verification failed\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">If your domain sends mail through external services such as MailerLite, Mailchimp, or Google Workspace, ensure the required DNS records have been configured correctly.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Relay_Access_Denied\"><\/span>Relay Access Denied<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Mail servers typically only allow authenticated users to send messages.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 Relaying denied\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">This usually indicates:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Incorrect SMTP authentication<\/li>\n\n\n\n<li>Wrong outgoing mail server settings<\/li>\n\n\n\n<li>Attempting to send through a server that does not authorize your account<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Spam_Detection\"><\/span>Spam Detection<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The recipient server may classify the message as spam and reject it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 Message rejected as spam\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Common triggers include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Excessive links<\/li>\n\n\n\n<li>Suspicious attachments<\/li>\n\n\n\n<li>Poor sender reputation<\/li>\n\n\n\n<li>Spam-like wording<\/li>\n\n\n\n<li>Missing email authentication records<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_to_Troubleshoot_Error_550\"><\/span>How to Troubleshoot Error 550<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"1_Review_the_Full_Error_Message\"><\/span>1. Review the Full Error Message<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The SMTP code alone rarely identifies the exact cause.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 User unknown\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">requires a different solution than:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>550 SPF validation failed\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Always review the complete bounce message.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2_Verify_the_Recipient_Address\"><\/span>2. Verify the Recipient Address<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Double-check:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Spelling<\/li>\n\n\n\n<li>Domain name<\/li>\n\n\n\n<li>Missing characters<\/li>\n\n\n\n<li>Accidental spaces<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"3_Check_SPF_DKIM_and_DMARC_Records\"><\/span>3. Check SPF, DKIM and DMARC Records<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If you manage your domain&#8217;s DNS zone, verify that:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SPF records are valid<\/li>\n\n\n\n<li>DKIM signing is enabled<\/li>\n\n\n\n<li>DMARC policy is configured correctly<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Authentication failures are among the most common causes of modern email rejection.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"4_Check_Server_Reputation\"><\/span>4. Check Server Reputation<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If all recipients reject messages from your domain, verify whether the sending IP address has been listed on spam blacklists.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A poor IP reputation can cause widespread delivery problems.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"5_Contact_the_Recipient\"><\/span>5. Contact the Recipient<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If the mailbox exists and your configuration appears correct, the recipient&#8217;s mail administrator may need to whitelist your domain or investigate local filtering rules.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Preventing_Error_550\"><\/span>Preventing Error 550<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">To reduce the risk of future delivery issues:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Use valid SPF, DKIM and DMARC records.<\/li>\n\n\n\n<li>Avoid sending unsolicited bulk emails.<\/li>\n\n\n\n<li>Keep website applications updated to prevent abuse by spammers.<\/li>\n\n\n\n<li>Secure all mailboxes with strong passwords.<\/li>\n\n\n\n<li>Monitor outgoing email activity and delivery logs regularly.<\/li>\n\n\n\n<li>Maintain a clean sender reputation.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Summary\"><\/span>Summary<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Error 550 indicates that the recipient&#8217;s mail server has permanently rejected a message. The most common causes include invalid recipient addresses, spam filtering, authentication failures, poor sender reputation, or incorrect mail server configuration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The fastest way to resolve the issue is to review the full SMTP error message, identify the exact rejection reason, and correct the underlying problem before resending the email.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n<\/div>","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"template":"","format":"standard","manualknowledgebasecat":[25,51],"manual_kb_tag":[1887,3856,3857,3858,3859,3860,3861,339,1441,1472],"class_list":["post-221","manual_kb","type-manual_kb","status-publish","format-standard","hentry","manualknowledgebasecat-hosting","manualknowledgebasecat-types-of-http-errors","manual_kb_tag-message-rejection","manual_kb_tag-error-55","manual_kb_tag-email-error-55","manual_kb_tag-mail-server-issues","manual_kb_tag-user-unknown","manual_kb_tag-relaying-denied","manual_kb_tag-sender-domain-not-found","manual_kb_tag-email-deliverability","manual_kb_tag-bounce-message","manual_kb_tag-mail-server-configuration"],"_links":{"self":[{"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/manual_kb\/221","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/manual_kb"}],"about":[{"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/types\/manual_kb"}],"author":[{"embeddable":true,"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":3,"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/manual_kb\/221\/revisions"}],"predecessor-version":[{"id":4897,"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/manual_kb\/221\/revisions\/4897"}],"wp:attachment":[{"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/media?parent=221"}],"wp:term":[{"taxonomy":"manualknowledgebasecat","embeddable":true,"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/manualknowledgebasecat?post=221"},{"taxonomy":"manual_kb_tag","embeddable":true,"href":"https:\/\/mybox.com\/help\/ro\/wp-json\/wp\/v2\/manual_kb_tag?post=221"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}