{"id":2521,"date":"2026-04-01T22:40:57","date_gmt":"2026-04-01T17:10:57","guid":{"rendered":"https:\/\/mukundasoftware.com\/blog\/?p=2521"},"modified":"2026-04-01T22:41:31","modified_gmt":"2026-04-01T17:11:31","slug":"fix-msoutlook-messages-stuck-in-outbox","status":"publish","type":"post","link":"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-msoutlook-messages-stuck-in-outbox.html","title":{"rendered":"Fix: MS Outlook Messages Stuck in Outbox \u2013 Emails Won\u2019t Send"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>TL;DR:<\/strong> Emails stuck in Outbox usually mean Outlook can\u2019t connect to the outgoing server or the message is corrupted. Try clearing the Outbox, disabling add\u2011ins, or checking SMTP authentication. Jump to Solution 1.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">You\u2019ve composed an email, clicked \u201c<strong>Send<\/strong>,\u201d but instead of moving to \u201c<strong>Sent Items<\/strong>,\u201d the message stays in the Outbox. Sometimes it shows <strong>\u201cSending\u2026<\/strong>\u201d forever; other times, it just sits there. This is one of the most common and frustrating Outlook issues.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The Outbox is a holding area for messages awaiting delivery. When emails get stuck, it\u2019s usually because Outlook can\u2019t complete the send operation. The good news is that the fix is often straightforward\u2014though it may require a few steps.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>What Causes Messages to Get Stuck in Outbox?<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Corrupt stuck message<\/strong> \u2013 The most common cause; a message that Outlook can\u2019t process.<\/li>\n\n\n\n<li><strong>Send\/Receive groups disabled<\/strong> \u2013 The automatic send\/receive schedule may be off.<\/li>\n\n\n\n<li><strong>Offline mode accidentally enabled<\/strong> \u2013 Outlook is in \u201cWork Offline\u201d mode.<\/li>\n\n\n\n<li><strong>Incorrect SMTP settings<\/strong> \u2013 Wrong port, encryption, or authentication.<\/li>\n\n\n\n<li><strong>Large attachment exceeding server limits<\/strong> \u2013 Many providers cap attachment sizes.<\/li>\n\n\n\n<li><strong>Modern authentication failure<\/strong> \u2013 OAuth2 token expired or app password incorrect.<\/li>\n\n\n\n<li><strong>Add\u2011in interference<\/strong> \u2013 Some add\u2011ins block sending.<\/li>\n\n\n\n<li><strong>Corrupt Outlook profile or PST<\/strong> \u2013 Profile or data file corruption.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>How to Fix Emails Stuck in Outbox<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Work through these solutions in order.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">1. Clear the Outbox<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The first step is to remove the problematic message.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Go to the <strong>Outbox<\/strong> folder in Outlook.<\/li>\n\n\n\n<li><strong>Check the message status:<\/strong>\n<ul class=\"wp-block-list\">\n<li>If the message is in <strong>italic<\/strong>, it\u2019s queued to send.<\/li>\n\n\n\n<li>If it\u2019s in <strong>bold<\/strong>, the user may have clicked back into it, and it\u2019s not actually queued. <strong>Re\u2011open the message and click \u201cSend\u201d again<\/strong> to make it italic and start the send process.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>If it\u2019s still stuck, right\u2011click the stuck message and select <strong>Delete<\/strong>.<br>(If you need the content, drag it to <strong>Drafts<\/strong> instead.)<\/li>\n\n\n\n<li>Compose a new test email (short, no attachments) and send it.<\/li>\n\n\n\n<li>If the test sends, the original message was corrupted.<\/li>\n<\/ol>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\ud83d\udca1 Pro Tip:<\/strong> If the Outbox appears empty but Outlook still says \u201cSending\u2026\u201d in the status bar, switch to <strong>Work Offline<\/strong> (Send\/Receive tab \u2192 Work Offline), restart Outlook, then go back online. This often flushes the stuck queue.<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2. Check Send\/Receive Groups<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Outlook may not be trying to send automatically.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Go to <strong>Send\/Receive<\/strong> tab \u2192 <strong>Send\/Receive Groups<\/strong> \u2192 <strong>Define Send\/Receive Groups<\/strong>.<\/li>\n\n\n\n<li>Ensure <strong>Schedule an automatic send\/receive every X minutes<\/strong> is checked.<\/li>\n\n\n\n<li>Verify <strong>Include this group in send\/receive<\/strong> is checked for your account group.<\/li>\n\n\n\n<li>Click <strong>Close<\/strong>, then manually click <strong>Send\/Receive All Folders<\/strong>.<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3. Double\u2011Toggle \u201cWork Offline\u201d Mode<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sometimes the status bar lies. A forced reset can help.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Go to <strong>Send\/Receive<\/strong> tab and click <strong>Work Offline<\/strong> to turn it <strong>on<\/strong>.<\/li>\n\n\n\n<li>Wait 5 seconds.<\/li>\n\n\n\n<li>Click <strong>Work Offline<\/strong> again to turn it <strong>off<\/strong>.<\/li>\n\n\n\n<li>This forces Outlook to reset its network stack and re\u2011establish connections.<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">4. Verify SMTP Settings &amp; Authentication<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect outgoing server settings are a major cause.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Go to <strong>File<\/strong> \u2192 <strong>Account Settings<\/strong> \u2192 <strong>Account Settings<\/strong>.<\/li>\n\n\n\n<li>Select your email account and click <strong>Change<\/strong>.<\/li>\n\n\n\n<li>Click <strong>More Settings<\/strong> \u2192 <strong>Outgoing Server<\/strong> tab.<\/li>\n\n\n\n<li>Check <strong>My outgoing server (SMTP) requires authentication<\/strong>.<br>(For most accounts, select <strong>Use same settings as my incoming mail server<\/strong>.)<\/li>\n\n\n\n<li>Go to the <strong>Advanced<\/strong> tab and verify:<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Setting<\/th><th>Recommended Value<\/th><\/tr><\/thead><tbody><tr><td>Outgoing Server<\/td><td>Your provider\u2019s SMTP (e.g., <code>smtp.gmail.com<\/code>)<\/td><\/tr><tr><td>Port<\/td><td><strong>587<\/strong> (STARTTLS) \u2013 preferred; <strong>465<\/strong> (SSL) \u2013 alternative<\/td><\/tr><tr><td>Encryption<\/td><td><strong>STARTTLS<\/strong> (for 587) or <strong>SSL\/TLS<\/strong> (for 465)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\u26a0\ufe0f Important:<\/strong> Many ISPs block port 25. Always use port 587 or 465.<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">5. Handle Large Attachments Offline<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">When a message is too large, Outlook may get stuck in an infinite retry loop, constantly failing at 99%.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Delete the large message while Outlook is Offline:<\/strong>\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Go to <strong>Send\/Receive<\/strong> tab and turn <strong>Work Offline<\/strong> <strong>on<\/strong>.<\/li>\n\n\n\n<li>Go to the Outbox, delete the large message.<\/li>\n\n\n\n<li>Turn <strong>Work Offline<\/strong> off again.<br>(This prevents Outlook from trying to send it while you\u2019re trying to delete it, which often results in \u201cThe operation cannot be performed.\u201d)<\/li>\n<\/ol>\n<\/li>\n\n\n\n<li><strong>Check attachment limits:<\/strong> Most providers cap attachments at <strong>25 MB<\/strong>. If you need to send larger files, use a file\u2011sharing service or compress the files.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">6. Run Outlook in Safe Mode &amp; Disable Add\u2011ins<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A faulty add\u2011in can interfere with sending.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Press <strong>Windows Key + R<\/strong>, type <code>outlook.exe \/safe<\/code>, and press <strong>Enter<\/strong>.<\/li>\n\n\n\n<li>If sending works in Safe Mode, disable add\u2011ins:\n<ul class=\"wp-block-list\">\n<li>Go to <strong>File<\/strong> \u2192 <strong>Options<\/strong> \u2192 <strong>Add\u2011ins<\/strong>.<\/li>\n\n\n\n<li>At the bottom, select <strong>COM Add\u2011ins<\/strong> and click <strong>Go<\/strong>.<\/li>\n\n\n\n<li>Uncheck all add\u2011ins, restart Outlook normally, and test.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Re\u2011enable them one by one to find the culprit.<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">7. Refresh Modern Authentication (OAuth2 \/ MFA)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In 2026, many stuck messages are caused by an expired OAuth2 token or a failed background MFA prompt. Outlook may silently fail in the Outbox instead of showing a login popup.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Refresh the token via web login:<\/strong>\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Log into your email account via the web (e.g., <a href=\"https:\/\/outlook.com\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">outlook.com<\/a> or Gmail).<\/li>\n\n\n\n<li>Complete any security prompts.<\/li>\n\n\n\n<li>Restart Outlook and test sending. This often \u201cunfreezes\u201d the desktop app\u2019s connection.<\/li>\n<\/ol>\n<\/li>\n\n\n\n<li><strong>For Microsoft 365 \/ Exchange:<\/strong><br>Go to <strong>File<\/strong> \u2192 <strong>Account Settings<\/strong> \u2192 <strong>Account Settings<\/strong> \u2192 select account \u2192 <strong>Change<\/strong>. Under <strong>Logon Information<\/strong>, ensure <strong>OAuth2<\/strong> is selected. Click <strong>Repair<\/strong> to refresh the token.<\/li>\n\n\n\n<li><strong>For Gmail \/ <a href=\"https:\/\/Outlook.com\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Outlook.com<\/a> \/ Yahoo:<\/strong><br>If you use 2FA, generate a new <strong>App Password<\/strong> from your account security page and update it in Outlook.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">8. Create a New Outlook Profile<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Profile corruption can cause the Outbox to freeze.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Close Outlook.<\/li>\n\n\n\n<li>Open <strong>Control Panel<\/strong> \u2192 <strong>Mail (Microsoft Outlook)<\/strong> \u2192 <strong>Show Profiles<\/strong>.<\/li>\n\n\n\n<li>Click <strong>Add<\/strong>, create a new profile, and set up your email account.<\/li>\n\n\n\n<li>Under \u201cWhen starting Microsoft Outlook,\u201d select <strong>Prompt for a profile<\/strong>.<\/li>\n\n\n\n<li>Open Outlook with the new profile. If sending works, you can make it the default.<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">9. Use the Microsoft Support and Recovery Assistant (SaRA)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">SaRA can automatically diagnose send issues.<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/aka.ms\/SaRA-Outlook\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Download the Microsoft Support and Recovery Assistant<\/a><\/strong>.<\/li>\n\n\n\n<li>Run it and select <strong>Outlook<\/strong> \u2192 <strong>I\u2019m having trouble sending or receiving email<\/strong>.<\/li>\n\n\n\n<li>Follow the prompts. SaRA will test settings and offer repairs.<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">10. Check with Your Email Provider or IT Admin<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If all else fails, the problem may be server\u2011side:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Personal accounts:<\/strong> Contact your hosting provider. They can check if SMTP is blocked or if your account is throttled.<\/li>\n\n\n\n<li><strong>Work\/school accounts:<\/strong> Your IT department may have disabled SMTP AUTH or require specific authentication methods.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Related Reading from Mukunda Software<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Explore our other Outlook troubleshooting guides:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-outlook-error-0x80042109-smtp-connection-failure.html\" target=\"_blank\" rel=\"noreferrer noopener\">Fix: Outlook Error 0x80042109 \u2013 SMTP Connection Failure<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-outlook-error-0x800ccc80-smtp-authentication.html\" target=\"_blank\" rel=\"noreferrer noopener\">Fix: Outlook Error 0x800CCC80 \u2013 SMTP Authentication Required<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-outlook-not-sending-receiving-emails.html\" target=\"_blank\" rel=\"noreferrer noopener\">Fix: Outlook Cannot Send\/Receive at All<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-outlook-error-0x800ccc0f-server-connection-interrupted.html\" target=\"_blank\" rel=\"noreferrer noopener\">Fix: Outlook Error 0x800CCC0F \u2013 Server Connection Interrupted<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-required-authentication-broker-missing-outlook.html\" target=\"_blank\" rel=\"noreferrer noopener\">Fix: Required Authentication Broker Missing<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>TL;DR: Emails stuck in Outbox usually mean Outlook can\u2019t connect to the outgoing server or the message is corrupted. Try clearing the Outbox, disabling add\u2011ins, or checking SMTP authentication. Jump to Solution 1. You\u2019ve composed an email, clicked \u201cSend,\u201d but instead of moving to \u201cSent Items,\u201d the message stays in the Outbox. Sometimes it shows &#8230; <a title=\"Fix: MS Outlook Messages Stuck in Outbox \u2013 Emails Won\u2019t Send\" class=\"read-more\" href=\"https:\/\/mukundasoftware.com\/blog\/help\/outlook\/fix-msoutlook-messages-stuck-in-outbox.html\" aria-label=\"Read more about Fix: MS Outlook Messages Stuck in Outbox \u2013 Emails Won\u2019t Send\">Read more<\/a><\/p>\n","protected":false},"author":4,"featured_media":2522,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[49],"tags":[202,200,201,203],"class_list":["post-2521","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-outlook","tag-microsoft-and-outlook","tag-microsoft-out-look","tag-ms-outlook","tag-msoutlook"],"_links":{"self":[{"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/posts\/2521","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/comments?post=2521"}],"version-history":[{"count":1,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/posts\/2521\/revisions"}],"predecessor-version":[{"id":2523,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/posts\/2521\/revisions\/2523"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/media\/2522"}],"wp:attachment":[{"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/media?parent=2521"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/categories?post=2521"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mukundasoftware.com\/blog\/wp-json\/wp\/v2\/tags?post=2521"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}