{"id":299,"date":"2025-04-24T10:57:25","date_gmt":"2025-04-24T10:57:25","guid":{"rendered":"https:\/\/bestosttopst.org\/blogs\/?p=299"},"modified":"2025-04-24T10:59:52","modified_gmt":"2025-04-24T10:59:52","slug":"understanding-ndr","status":"publish","type":"post","link":"https:\/\/bestosttopst.org\/blogs\/understanding-ndr\/","title":{"rendered":"Understanding NDR: Email Delivery Issues &#038; Fixes"},"content":{"rendered":"<p><span data-contrast=\"auto\">NDR (Non-Delivery Report) is also known as Delivery Station Notification (DSN). <\/span><span data-contrast=\"none\">\u202f<\/span><span data-contrast=\"none\">When you send an\u202femail and it can\u2019t be delivered,<\/span> <span data-contrast=\"auto\">you will receive a bounce-back notification explaining why their email did not reach the recipient, it could be due to an invalid email address, spam, etc.\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><span data-contrast=\"auto\">You can picture the postman taking a postcard from the sender and returning it to the sender with a note explaining why his post was not delivered to the recipient because of an address issue.\u202f<\/span><\/p>\n<h2><b><span data-contrast=\"auto\">How does a Non-Delivery Report generate?<\/span><\/b><span data-contrast=\"auto\">\u202f<\/span><\/h2>\n<p><span data-contrast=\"none\">NDR report is generated when email cannot be delivered to recipient addresses, or the recipient mail server rejects an email due to the following reasons:<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/p>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"9\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"none\">Recipient&#8217;s address not found<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"9\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"2\" data-aria-level=\"1\"><span data-contrast=\"none\">DNS or routing problem<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"9\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"3\" data-aria-level=\"1\"><span data-contrast=\"none\">Message times out on delivery<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"9\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"4\" data-aria-level=\"1\"><span data-contrast=\"none\">Email is marked as spam<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"9\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"5\" data-aria-level=\"1\"><span data-contrast=\"none\">Sender was not authenticated by organization<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><\/li>\n<\/ul>\n<h3><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\">\u00a0<\/span><b><span data-contrast=\"auto\">What is included in the NDR?<\/span><\/b><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/h3>\n<p><span data-contrast=\"auto\">The NDR is designed in such an easy format that every email user and administrator can understand it. It will also tell you how to resolve the issue and what steps to take to fix it.\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-300\" src=\"http:\/\/bestosttopst.org\/blogs\/wp-content\/uploads\/2025\/04\/NDR-1.png\" alt=\"NDR-1\" width=\"358\" height=\"458\" srcset=\"https:\/\/bestosttopst.org\/blogs\/wp-content\/uploads\/2025\/04\/NDR-1.png 358w, https:\/\/bestosttopst.org\/blogs\/wp-content\/uploads\/2025\/04\/NDR-1-234x300.png 234w\" sizes=\"(max-width: 358px) 100vw, 358px\" \/><\/p>\n<p><span data-contrast=\"auto\">\u202f<\/span><span data-contrast=\"auto\">The information mentioned in the NDR is used to resolve the issue immediately, and if a quick solution is not possible<\/span><span data-contrast=\"none\">, you can visit detailed reference article mentioned in the report, which helps you understand the problem mentioned in the code and how to fix it.\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"auto\">1-Cause:<\/span><\/b><span data-contrast=\"auto\"> It will first explain why the message was not delivered.\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><strong>2-<\/strong><b><span data-contrast=\"auto\">Owner <\/span><\/b><b><span data-contrast=\"none\">Indicator:<\/span><\/b> <span data-contrast=\"none\">This is an overview of the problem we encountered, and it explains who should\u202fresolve it. It is divided into three parts: the sender, Microsoft 365 or Office 365, and the recipient. The red indicator tells you who needs to resolve the problem.\u202f<\/span><\/p>\n<p><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<strong>3-<\/strong><\/span><b><span data-contrast=\"none\">How to correct it:<\/span><\/b><span data-contrast=\"none\"> This section is for the sender, which describes how issues can be fixed.\u202f<\/span><\/p>\n<p><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><b><span data-contrast=\"none\">4- More info for email Admins:<\/span><\/b><span data-contrast=\"none\"> This section explains the problem in detail and provides a solution along with a web link to a detailed article that helps solve the issue.<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><b><span data-contrast=\"none\">5-Message hops:<\/span><\/b><span data-contrast=\"none\"> This is like a travel history of the message and helps to identify where it had errors.<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-301\" src=\"http:\/\/bestosttopst.org\/blogs\/wp-content\/uploads\/2025\/04\/NDR-2.png\" alt=\"NDR-2\" width=\"369\" height=\"472\" srcset=\"https:\/\/bestosttopst.org\/blogs\/wp-content\/uploads\/2025\/04\/NDR-2.png 369w, https:\/\/bestosttopst.org\/blogs\/wp-content\/uploads\/2025\/04\/NDR-2-235x300.png 235w\" sizes=\"(max-width: 369px) 100vw, 369px\" \/><\/p>\n<h3><b><span data-contrast=\"none\">Some of the NDR codes<\/span><\/b><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/h3>\n<p><b><span data-contrast=\"none\">NDR 5.1.1 Bad destination mailbox address: <\/span><\/b><span data-contrast=\"none\">This error occurs when the sender enters the wrong recipient address or the recipient mailbox address has been changed, and you are trying to send to the old address, which was correct before but has now been changed.<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"none\">NDR 5.2.2 Submission quota exceeded: <\/span><\/b><span data-contrast=\"none\">This means that the sender has exceeded the message limit.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"none\">Code 5.7.1 Delivery not authorized:<\/span><\/b> <span data-contrast=\"none\">This happens when the sender tries to send an email to a recipient, but the sender doesn&#8217;t have permission. This usually happens when only members of the organization are allowed to send emails.<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><b><span data-contrast=\"none\">Code 4.4.7 Message Expired:<\/span><\/b> <span data-contrast=\"none\">It means there is a problem on the receiving server, check the validity of the recipient address. Find out whether recipient is configured correctly to receive a message.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<p><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><b><span data-contrast=\"none\">Code 5.4.1 Recipient address rejected, or Access denied:<\/span><\/b> <span data-contrast=\"none\">It will tell you that the person you are trying to send a message is does not exist. In that case, you must check the address and see if there is any spelling mistake or if the entire address is wrong.<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<h3><span data-contrast=\"auto\">\u202f<\/span><b><span data-contrast=\"auto\">Why is understanding the Non-Delivery Report is important?<\/span><\/b><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/h3>\n<p><span data-contrast=\"auto\">It is important to understand NDR for system administrators, the desk help team, and even for regular users.<\/span><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"3\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;multilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"auto\">Deliverability of emails improves.<\/span><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559685&quot;:1080,&quot;335559731&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"4\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;multilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"none\">Improves customer satisfaction<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559685&quot;:1080,&quot;335559731&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"5\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;multilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"none\">Helps in smooth communication<\/span><span data-contrast=\"none\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559685&quot;:1080,&quot;335559731&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/li>\n<\/ul>\n<h3><b><span data-contrast=\"auto\">Troubleshoot NDR<\/span><\/b><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/h3>\n<p><span data-contrast=\"auto\">Understand the NDR details such as error codes, email addresses and reasons why emails were not delivered.<\/span><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/p>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"6\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;multilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"auto\">Check the recipient&#8217;s email address, such as if there are any typing errors. If the email account, you&#8217;re trying to send to is not active.<\/span><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559685&quot;:1080,&quot;335559731&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"7\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;multilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"auto\">Use message hops which track the path of the message. It tell you where it got rejected or the failure point.<\/span><span data-contrast=\"auto\">\u202f<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559685&quot;:1080,&quot;335559731&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/li>\n<\/ul>\n<ul>\n<li data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"8\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;multilevel&quot;}\" aria-setsize=\"-1\" data-aria-posinset=\"1\" data-aria-level=\"1\"><span data-contrast=\"auto\">Check mail flow rules, recipient existence.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;201341983&quot;:0,&quot;335559685&quot;:1080,&quot;335559731&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0,&quot;335559740&quot;:240}\">\u00a0<\/span><\/li>\n<\/ul>\n<h4><b><span data-contrast=\"auto\">Conclusion:<\/span><\/b><span data-contrast=\"auto\"> \u202f<\/span><\/h4>\n<p>In this article, we have learned about NDR, what it consists of, and the meaning of NDR codes. Whether you are a regular email user or admin, understanding the NDR can save a lot of time. It can help resolve issues easily.<\/p>\n<p><span data-contrast=\"auto\">If you liked this article, you might also find this article interesting: <\/span><a href=\"https:\/\/bestosttopst.org\/blogs\/assign-and-manage-delegation-to-mailboxes-in-m365\/\">Manage mailboxes delegation in M365<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>NDR (Non-Delivery Report) is also known as Delivery Station Notification (DSN). \u202fWhen you send an\u202femail and it can\u2019t be delivered, you will receive a bounce-back notification explaining why their email did not reach the recipient, it could be due to an invalid email address, spam, etc.\u202f\u00a0 You can picture the postman taking a postcard from [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":302,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-299","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v23.1 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Understanding NDR: Email Delivery Issues &amp; 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