{"id":3836,"date":"2024-04-01T15:53:15","date_gmt":"2024-04-01T15:53:15","guid":{"rendered":"https:\/\/www.warmy.io\/blog\/how-to-fix-smtp-email-error-553-5-1-3-solved\/"},"modified":"2026-04-06T10:46:03","modified_gmt":"2026-04-06T10:46:03","slug":"how-to-fix-smtp-email-error-553-5-1-3-solved","status":"publish","type":"post","link":"https:\/\/www.warmy.io\/blog\/how-to-fix-smtp-email-error-553-5-1-3-solved\/","title":{"rendered":"SMTP Error 553 5.1.3: How to Fix It [SOLVED]"},"content":{"rendered":"<p><span>Email is still a crucial tool in our digital age. It continues to power communication for businesses and individuals alike. It fuels connections, nurtures leads, and drives sales. But every once in a while, a nightmare can strike. Your beautifully crafted emails that you spent hours working on never reached their intended recipient\u2014the horror! One frequent culprit behind failed deliveries is SMTP Email Error 553 5.1.3.<\/span><\/p>\n<p><span>While frustrating indeed, this error has a fix. So don\u2019t fret. Like the other errors under the <\/span><a href=\"https:\/\/www.warmy.io\/blog\/what-is-smtp-and-how-does-the-smtp-server-work\/\" target=\"_blank\" rel=\"noopener noreferrer\"><span>Simple Mail Transfer Protocol (SMTP)<\/span><\/a><span> family, SMTP Email Error 553 5.1.3 can also be conquered.<\/span><\/p>\n<p><span>This guide contains the specifics of SMTP Email Error 553 5.1.3. We\u2019ve also compiled solutions to keep your email communication smooth and stress-free, ensuring your emails land in inboxes.<\/span><\/p>\n<h2>Defining SMTP Email Error 553 5.1.3<br \/>\n<\/h2>\n<p><iframe width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/2QAK7fPKBMs\" frameborder=\"0\" allowfullscreen allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\"><\/iframe><\/p>\n<p><span>This error means there\u2019s a problem or issue with the format of the recipient\u2019s email address. Maybe there\u2019s a typo. Some special characters are unsupported. Sometimes, the email address format is not recognized as valid by the email server.<\/span><\/p>\n<p><span>Users encountering this issue might see messages such as:<\/span><\/p>\n<ul>\n<li><span>\u201c553 5.1.3 The recipient address &lt;email_address&gt; is not a valid RFC-5321 address.\u201d<\/span><\/li>\n<li><span>\u201cError 553 5.1.3: &lt;email_address&gt;\u2026 User address is malformed.\u201d<\/span><\/li>\n<li><span>\u201cFailed to send; SMTP server error 553 5.1.3 &lt;email_address&gt;\u2026 Syntax error in mailbox address.\u201d<\/span><\/li>\n<\/ul>\n<h2>Root causes of SMTP Email Error 553 5.1.3<br \/>\n<\/h2>\n<p>SMTP Email Error 553 5.1.3 can arise from several factors, primarily related to issues with the email address format being sent to. Understanding these common causes can help in effectively diagnosing and solving the problem:<\/p>\n<h3>Incorrect email address<br \/>\n<\/h3>\n<p><span>The most straightforward reason is simply <\/span><b>typing the email address incorrectly.<\/b><span> This could mean misspelling the address, omitting characters, or including spaces and special characters that aren\u2019t typically part of email formats.<\/span><\/p>\n<h3>Improper email format<br \/>\n<\/h3>\n<p><span>Some email servers have <\/span><b>strict rules about which characters can appear in an email address<\/b><span>. <\/span><span>Using unsupported characters (even if they\u2019re technically valid in other contexts) can trigger SMTP Email Error 553 5.1.3.<\/span><\/p>\n<h3>Unsupported characters<br \/>\n<\/h3>\n<p><span>Email addresses should always follow a specific format, which is <\/span><a href=\"mailto:name@domain.com\" target=\"_blank\" rel=\"noopener noreferrer\"><span>name@domain.com<\/span><\/a><span>. So if an email address doesn\u2019t follow this, or misses the \u201c@\u201d symbol or the domain part, this will lead to an error.<\/span><\/p>\n<h3>Misconfigurations in email client<br \/>\n<\/h3>\n<p><span>Sometimes, the way an email client (like Outlook or Gmail) is configured can cause it to incorrectly format outgoing email addresses<\/span><span>. Yes, even if you\u2019ve entered them correctly.<\/span><\/p>\n<h3>Issues with mail exchange records<\/h3>\n<p><span>Misconfigured MX records on the receiver\u2019s end can lead to undelivered emails. <\/span><span>Though this can also generate different error codes, it\u2019s still worth reviewing if the format is correct.<\/span><\/p>\n<h2>Troubleshooting guide to resolving SMTP Email Error 553 5.1.3<br \/>\n<\/h2>\n<p><span>There\u2019s no need to worry when you see this error. However, knowing how to resolve this will help you determine your next steps.<\/span><\/p>\n<h3>For Gmail users<br \/>\n<\/h3>\n<ul>\n<li><b>Verify email address format.<\/b><span> Review the recipient\u2019s email address for any typos or formatting errors. Make sure it follows the required format.<\/span><\/li>\n<li><b>Check account settings.<\/b><span> Go to Settings &gt; See all settings &gt; Accounts and Import. Under \u201cSend mail as,\u201d ensure the email address is correctly formatted and verified.<\/span><\/li>\n<li><b>Review SMTP settings.<\/b><span> Ensure that the SMTP server is set to smtp.gmail.com, the port is set to 587 (for TLS) or 465 (for SSL), and that \u201cUse Authentication\u201d is enabled with your correct Gmail address and password<\/span><\/li>\n<\/ul>\n<h3>For Outlook users<\/h3>\n<ul>\n<li><b>Verify your email address. <\/b><span>Similar to Gmail, start by reviewing and verifying the format of the recipient\u2019s email address.<\/span><\/li>\n<li><b>Adjust email account settings. <\/b><span>Head over to File &gt; Account Settings &gt; Server Settings. Click on Outgoing Mail and confirm the SMTP settings are correct: server smtp-mail.outlook.com, port 587, and encryption method TLS.<\/span><\/li>\n<li><b>Ensure correct authentication. <\/b><span>Look for \u201cMy outgoing (SMTP) server requires authentication\u201d and \u201cUse the same settings as my incoming mail server\u201d and ensure they are checked or selected.<\/span><\/li>\n<\/ul>\n<h3>For Yahoo! users<\/h3>\n<ul>\n<li><b>Check the recipient\u2019s email address.<\/b><span> Make sure it is free of errors and formatted correctly.<\/span><\/li>\n<li><b>Review your SMTP configuration settings.<\/b><span> Go to Account Info &gt; Account Security &gt; Manage App Passwords. Select your <a href=\"https:\/\/emailsorters.com\/blog\/best-free-email-apps-android\/\" rel=\"noopener\" target=\"_blank\" rel=\"noopener noreferrer\">email app<\/a> and generate a unique app password. Use this app password with your email address to authenticate your SMTP server.<\/span><\/li>\n<li><b>Check your SMTP server details. <\/b><span>Set to smtp.mail.yahoo.com, with port 465 (SSL required) or 587 (TLS required).<\/span><\/li>\n<\/ul>\n<h2>How email warmup services help in reducing SMTP Email Error 553 5.1.3<br \/>\n<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" alt=\"warmy dashboard\" height=\"600\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2024\/01\/11093951\/warmy-dashboard-1024x768.png\" width=\"800\" title=\"\"><\/p>\n<p><span>Email warmup tools don\u2019t just help prevent SMTP errors. It\u2019s more for the long run. <\/span><a href=\"https:\/\/www.warmy.io\/\" rel=\"noopener\" target=\"_blank\" rel=\"noopener noreferrer\"><span>Warmy.io<\/span><\/a><span>, for example, not only reduces the chances of encountering errors like SMTP Email Error 553 5.1.3, it also gradually builds your sender reputation. Warmy.io does this by gradually increasing the volume of emails sent from your email, mimicking human-like activity to establish your reputation with email service providers and ISPs.<\/span><\/p>\n<h3>Benefits of using email warmup services:<br \/>\n<\/h3>\n<ol>\n<li><b>Builds sender reputation. <\/b><span>Sending more emails gradually over time helps in building a positive sender reputation.\u00a0<\/span><\/li>\n<li><b>Reduces<\/b><a href=\"https:\/\/www.warmy.io\/blog\/bounced-emails-solutions-gmail-outlook-yahoo\/\" target=\"_blank\" rel=\"noopener noreferrer\"><b> email bounces<\/b><\/a><b>.<\/b><span> When you have a better sender reputation, this reduces the likelihood of your emails bouncing or being marked as spam.<\/span><\/li>\n<li><b>Prevents blacklisting.<\/b><span> A good sender reputation also helps in <\/span><a href=\"https:\/\/www.warmy.io\/blog\/email-domain-ip-blacklist-removal-steps-to-delist-your-ip\/\" target=\"_blank\" rel=\"noopener noreferrer\"><span>preventing your email domain from being blacklisted<\/span><\/a><span> by major email service providers. It sends a message that you are safe and you are reliable.<\/span><\/li>\n<li><b>Improves email engagement rates.<\/b><span> Emails that land in inboxes have bigger chances to be opened, read, and clicked on. So this essentially improves overall engagement rates.<\/span><\/li>\n<\/ol>\n<p><span>Warmy.io also offers additional tools that complement its warmup service, further ensuring your emails are delivered successfully:<\/span><\/p>\n<ul>\n<li><a href=\"https:\/\/www.warmy.io\/free-tools\/email-deliverability-test\" target=\"_blank\" rel=\"noopener noreferrer\"><b>Free Email Deliverability Test.<\/b><\/a> <span>Get the real deal and valuable insights on how likely your emails are to be delivered to your recipient\u2019s inbox, providing insights on areas for improvement.<\/span><\/li>\n<li><b>Blacklist Checks.<\/b><span> Warmy.io can check if your email domain has been blacklisted, which is a common cause of email delivery issues.<\/span><\/li>\n<li><b>SPF and DMARC Record Generators.<\/b><span> Warmy.io provides tools to generate these records for free, helping you comply with email security standards and improve deliverability.<\/span><\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" alt=\"SPF generator\" height=\"600\" src=\"https:\/\/warmy-blog-wordpress-bucket.s3.amazonaws.com\/wp-content\/uploads\/2024\/01\/11093955\/SPF-generator-1-1024x768.jpg\" width=\"800\" title=\"\"><\/p>\n<h2>Overcome SMTP Email Error 553 5.1.3 and get your emails to your target inbox with Warmy.io<br \/>\n<\/h2>\n<p><span>Addressing SMTP Email Error 553 5.1.3 quickly is crucial for maintaining uninterrupted email communication, crucial for today\u2019s digital interactions. <\/span><span>This guide has provided practical solutions for popular email platforms and highlighted the preventive benefits of email warmup services like Warmy.io.\u00a0<\/span><\/p>\n<p><span>These strategies can ensure your emails consistently reach their intended recipients. So take action now to safeguard your email delivery and keep your professional connections strong.<\/span><\/p>\n<p><b>\ud83d\udcdc Related articles:<\/b><\/p>\n<p><span>\u25fe<\/span><a href=\"https:\/\/www.warmy.io\/blog\/how-to-fix-smtp-email-error-553-solved\/\" target=\"_blank\" rel=\"noopener noreferrer\"><span>SMTP Email Error 553 \u2013 How to Resolve [SOLVED]<\/span><\/a><span>\u25fe<\/span><a href=\"https:\/\/www.warmy.io\/blog\/how-to-fix-smtp-email-error-553-5-3-0-solved\/\" target=\"_blank\" rel=\"noopener noreferrer\"><span>SMTP Email Error 553 5.3.0- How to Resolve [SOLVED]<\/span><\/a><span>\u25fe<\/span><a href=\"https:\/\/www.warmy.io\/blog\/how-to-fix-smtp-email-error-553-5-7-1-solved\/\" target=\"_blank\" rel=\"noopener noreferrer\"><span>SMTP Email Error 553 5.7.1- How to Resolve [SOLVED]<\/span><\/a><\/p>\n<h2>FAQ<\/h2>\n<h3>\n<p> Why does SMTP Email Error 553 5.1.3 happen? <\/p>\n<\/h3>\n<p><span>Incorrect email address formatting, typos, unsupported characters, or incomplete addresses cause this error. Misconfigurations in your email client settings can also trigger this.<\/span><\/p>\n<h3>\n<p> How can SMTP Email Error 553 5.1.3 be prevented? <\/p>\n<\/h3>\n<p><span>Prevention starts with ensuring all email addresses are correctly formatted before sending. Regularly review and update your email client settings to match your email service provider&#8217;s recommendations. Using email validation tools can also help catch errors before sending.<\/span><\/p>\n<h3>\n<p> Are there long-term fixes for SMTP Email Error 553 5.1.3? <\/p>\n<\/h3>\n<p><span>Yes, establishing rigorous checks for email address validity and maintaining up-to-date email client configurations serve as long-term solutions.<\/span><span> Additionally, implementing email warm-up practices can improve your sender reputation, reducing the likelihood of such errors.<\/span><\/p>\n<h3>\n<p> Can email warmup services prevent SMTP errors? <\/p>\n<\/h3>\n<p><span>Yes! Services like Warmy.io gradually increase your email sending volume, helping to build a positive sender reputation. Not only does it prevent SMTP Email Error 553 5.1.3, it can also tackle other delivery issues by ensuring your emails are recognized as legitimate.<\/span><\/p>\n<h3>\n<p> What should I do if I continue to experience SMTP Email Error 553 5.1.3 despite corrections? <\/p>\n<\/h3>\n<p><span>Double-check for any overlooked misconfigurations in your email settings. Consult your email service provider or email deliverability experts. External factors, such as server issues on the recipient&#8217;s end, can also play a role.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Email is still a crucial tool in our digital age. It continues to power communication for businesses and individuals alike. It fuels connections, nurtures leads, and drives sales. But every once in a while, a nightmare can strike. Your beautifully crafted emails that you spent hours working on never reached their intended recipient\u2014the horror! One [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":4616,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[104],"tags":[],"class_list":["post-3836","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-email-deliverability"],"acf":[],"lang":"en","translations":{"en":3836},"pll_sync_post":[],"_links":{"self":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/3836","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/comments?post=3836"}],"version-history":[{"count":2,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/3836\/revisions"}],"predecessor-version":[{"id":5824,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/posts\/3836\/revisions\/5824"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/media\/4616"}],"wp:attachment":[{"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/media?parent=3836"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/categories?post=3836"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.warmy.io\/blog\/wp-json\/wp\/v2\/tags?post=3836"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}