{"id":1668,"date":"2021-05-20T09:34:05","date_gmt":"2021-05-20T06:34:05","guid":{"rendered":"https:\/\/www.scalahosting.com\/kb\/?p=1668"},"modified":"2021-05-20T09:40:48","modified_gmt":"2021-05-20T06:40:48","slug":"smtp-error-550","status":"publish","type":"post","link":"https:\/\/www.scalahosting.com\/kb\/smtp-error-550\/","title":{"rendered":"SMTP Error 550"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">An email error code indicates an unsuccessful email transaction between the sender and recipient\u2019s server.\u00a0<\/span><\/p>\n<p><b>SMTP error 550 <\/b><span style=\"font-weight: 400;\">is one of such errors that suggests your recipient\u2019s server bounced your incoming message.<\/span><\/p>\n<h2><b>What Does SMTP Error 550 Mean?<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">In simplest terms, the 550 error message means the receiver\u2019s mail server blocked your message and sent it back to you.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Unlike <\/span><b>the SMTP 554 error <\/b><span style=\"font-weight: 400;\">caused by the recipient or sender\u2019s server, the 550 email error is often caused by the recipient\u2019s server.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The 550 error code message has different variations. Decoding them is the first step to fixing the issue. Here are <\/span><b>examples of some common ones:<\/b><\/p>\n<ul>\n<li><span style=\"font-weight: 400;\">SMTP Error 5.5.0<\/span><\/li>\n<li><span style=\"font-weight: 400;\">550 User account is unavailable<\/span><\/li>\n<li><span style=\"font-weight: 400;\">550 No such user here<\/span><\/li>\n<li><b>Remote host said: 550 \u2014<\/b><span style=\"font-weight: 400;\"> user@sampleyourdomain.com, this domain [recipient\u2019s domain] Mailbox Does Not Exist \u2014 Giving up<\/span><\/li>\n<li aria-level=\"1\"><b>231.231.231.231 does not like recipient<\/b><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">Remote host said: 550-Verification failed for user@sampleyourdomain.com<\/span><\/p>\n<p><span style=\"font-weight: 400;\">550-Previous (cached) callout verification failure<\/span><\/p>\n<p><span style=\"font-weight: 400;\">550 Sender verification failed. Giving up on 231.231.231.231<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Although you might see these messages above (or a variation of them), you can also see a 5.1.0 error message that looks like this:<\/span><\/p>\n<p><b>5.1.0 &#8211;<\/b> <i><span style=\"font-weight: 400;\">Unknown address error 550-&#8216;Mailbox is inactive&#8217;<\/span><\/i><\/p>\n<p><span style=\"font-weight: 400;\">This occurs when a recipient\u2019s server is down due to a system-wide problem.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Now you know how <\/span><b>a basic 550 error message<\/b><span style=\"font-weight: 400;\"> looks like, let\u2019s go on to what causes this error and how to fix it.<\/span><\/p>\n<h2><b>What Causes a 550 Error and How to Fix it?<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">There are a few reasons why you could be receiving <\/span><b>SMTP Error 550.<\/b><span style=\"font-weight: 400;\"> The most common cause is that the receiving email server has rejected your email for one of the following reasons:<\/span><\/p>\n<h3><b>1. Invalid Recipient Address<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">This occurs when there\u2019s a typo in<\/span><b> the recipient\u2019s email address or extra spaces<\/b><span style=\"font-weight: 400;\">. Ensure that you have the correct email address from the recipient, or make sure you typed in the correct characters.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If this doesn\u2019t solve it, it could be that you have the wrong email address, or the recipient now uses a different domain or new address.<\/span><\/p>\n<h3><b>2. Bad Domain Reputation<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">This means the recipient\u2019s server doesn&#8217;t trust the domain name you are using. If this happens, then your email <\/span><b>IP is blacklisted<\/b><span style=\"font-weight: 400;\">, and your messages will bounce.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Reasons for this could be your system has a virus or malware, and:<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Someone is exploiting <\/span><b>a webmail app\u2019s <\/b><span style=\"font-weight: 400;\">vulnerability and uploading a spam script.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Or, that person has access to your account and is using it to send spam messages.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Either way, to fix this, you\u2019ll need to check if your IP address is blacklisted and send a delist request from the public RBL database.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Another option is <\/span><b>to install malware scanners on your system. <\/b><span style=\"font-weight: 400;\">This will scan outgoing emails and alert you if your email account is compromised. While you\u2019re at it, notify our support team of the issue immediately.<\/span><\/p>\n<h3><b>3. Server Downtime\u00a0<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">The receiving email server is currently not available due to a planned downtime or some technical problems. If it\u2019s urgent,<\/span><b> request an alternative email or try resending your email after a few hours.<\/b><\/p>\n<h3><b>4. Email Policy Violation<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Sometimes, the recipient\u2019s server may be<\/span><b> blocking your message due to an email policy violation.<\/b><span style=\"font-weight: 400;\"> You\u2019ll need to ensure you have everything fixed on your end. Do away with bulky attachments, spam words, and bad headers, as these are common policy violations for major email providers.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If you\u2019re not sure, read the email policy of <\/span><b>your email service provider.<\/b><\/p>\n<h3><b>5. Bulky Messages<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">The receiving email server might block a message when it\u2019s too bulky. You could split your messages into parts and send them separately or compress your attachments into a zip file.<\/span><\/p>\n<h3><b>6. Bad DNS Records<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">When this happens, it means your mail server has a mismatch of <\/span><a href=\"https:\/\/www.scalahosting.com\/kb\/dns-records-explained\/\"><span style=\"font-weight: 400;\">DNS records<\/span><\/a><span style=\"font-weight: 400;\">, or there is no available reverse DNS record for your IP address.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">This error is depicted with the message: \u201c550 reverse DNS\u201d. Please contact us to reconfigure your SMTP server configurations and check your DNS records.<\/span><\/p>\n<h3><b>7. ISP Restriction<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">The network administrators <\/span><i><span style=\"font-weight: 400;\">(those who manage ISP servers)<\/span><\/i><span style=\"font-weight: 400;\"> place restrictions on mail servers that often carry spam messages.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">When the junk email from a specific<\/span><b> SMTP server increases, <\/b><span style=\"font-weight: 400;\">it blocks it to prevent spam on their network. Contact your ISP providers to resolve this issue.<\/span><\/p>\n<h3><b>8. Compromised SMTP Port<\/b><\/h3>\n<p><span style=\"font-weight: 400;\">Since spammers often use port 25 to send spam messages, <\/span><b>the recipient\u2019s server can block your email if it uses the same mail port.\u00a0<\/b><\/p>\n<p><b>Change the port to 2525, 26, 887, or 465,<\/b><span style=\"font-weight: 400;\"> and see what happens.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">These errors and fixes above are not exhaustive, but these are the common ones you should be able to fix quickly. We also recommend that <\/span><b>you update your passwords regularly<\/b><span style=\"font-weight: 400;\"> and use email security software to prevent outsider access to your email account.<\/span><\/p>\n<h2><b>Need Help?<\/b><\/h2>\n<p><span style=\"font-weight: 400;\">Now you understand the SMTP Error 550, you might need any help with any thing related to the points we discussed here. If that\u2019s the case, please <\/span><a href=\"https:\/\/www.scalahosting.com\/contact-us.html\"><span style=\"font-weight: 400;\">contact our support at any time<\/span><\/a><span style=\"font-weight: 400;\">. We are available, around the clock.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>An email error code indicates an unsuccessful email transaction between the sender and recipient\u2019s server.\u00a0 SMTP error 550 is one of such errors that suggests your recipient\u2019s server bounced your incoming message. What Does SMTP Error 550 Mean? In simplest terms, the 550 error message means the receiver\u2019s mail server blocked your message and sent [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","footnotes":""},"categories":[26],"tags":[],"class_list":["post-1668","post","type-post","status-publish","format-standard","hentry","category-email-hosting"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/posts\/1668","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/comments?post=1668"}],"version-history":[{"count":1,"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/posts\/1668\/revisions"}],"predecessor-version":[{"id":1669,"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/posts\/1668\/revisions\/1669"}],"wp:attachment":[{"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/media?parent=1668"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/categories?post=1668"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.scalahosting.com\/kb\/wp-json\/wp\/v2\/tags?post=1668"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}