Microsoft Outlook is the most popular email and application manager because it’s creators carefully built an aura of dependability and security around it. But the reality is, Outlook is far from being worthy of our full trust. I say this because Outlook seems to have a habit of not sending important emails at the most inopportune times. At least in my case, it has. But as it turns out, the web is full of people with emails stuck in their Outlook’s Inbox and the causes are multiple. The issue usually goes like this – You write the email and hit the Send button. After a while, you find out that the email is still in the Outbox folder with no intention of ever leaving. Unfortunately, there are many reasons why Outlook wouldn’t send an email, so prepare for some extensive troubleshooting. Lucky for you, we collected the most effective troubleshooting instructions and put together a series of methods that will help you send emails normally in Outlook. But before we get to the actual guides, let me walk through the most common causes that will make your Outlook program unable to send emails:

Email has a huge attachment that slows or halts the sending process.The email was sent using Comcast account that a different outgoing server.An add-in marks the item as read when you view the Outbox.Account password was recently changed.Account not authentication properly with the mail server.Outlook server or mail server is offline.Outlook has no default email account.Corrupted Send and Receive settings.Another program is accessing the PST or OST data (Desktop Search, Lync, etc).An antivirus program is currently scanning the outgoing email.Outlook cannot connect to the email server.

Now that we know the culprits, let’s get busy. Below you have a collection of methods that have helped a lot of users to send emails again in Outlook. Follow each guide in order until you find a fix that works for you. Let’s begin.

Method 1: Make sure the servers are online

Before you go ahead and make changes that can potentially affect the way your Outlook works, let’s eliminate causes that are beyond our reach. The first thing you should check is the state of the mail server. If your mail server is currently offline, your email will be retained in the Outbox folder until the issue is sorted out.  A quick way to check the state of your mail server is to look in the lower right-hand corner of the Outlook window. If it says “Connected” or “Connected to Microsoft Exchange”, the error is not related to the server status. If it says “Working Offline”, you need to open the Send / Recieve tab and click on the Work Offline button to disable it. But keep in mind that you might need to open the email and send it again for it to send properly. In the event that it displays “Disconnected”, make sure your internet connection is working properly. The quickest way to do this is to open your browser and surf the internet. If you weren’t able to load any web pages in the browser, it’s clear that you have an internet connectivity problem.

Method 2: Resend the email message

Before you get technical with the methods below, it’s worth trying to send the email again an see if it manages to leave the Outlook folder. If you open the email from the Outbox folder while it’s being sent, Outlook won’t remove it from that folder even if the email was successfully sent. A quick way to check if the email was already sent is to open the email and try to re-send it manually. You can do this easily by accessing the outlook folder and clicking on the Send button again.

Method 3: Deleting large attachments

Most email providers (especially free providers) impose a limit upon the maximum size of attachments. This means that adding pictures, videos, and other large attachments to your emails can prevent you from sending that message and any message sent after a large message. The vast majority of email providers don’t allow attachments larger than 20- 25 MB. And even if the size is under the threshold of your email provider, it might still take a lot of time to send it if you have a poor internet connection. This could lead you to believe that the message is stuck in the Outbox folder. If you have at least one email that contains an attachment in your Outlook folder, delete it and try sending a test email without any attachment. You can do this easily by opening the Outlook folder, right-click on the email that refuses to send and click Delete.

As a rule of thumb, always use download links fo attachments larger than 10 MB. This way, you will avoid a lot of inconveniences.

Method 4: Syncing the account password

Internet mail provides tightened its security over the past couple of years. Aside from one or two-factor authentication, they also track the general location where a user usually accesses its mail from. If someone repeatedly tries to enter your account information from the other part of the globe, they will lock your mail account automatically. You’ll either be prompted to change your password or you’ll have to go over some authentication steps. If you recently changed your email password, there’s a strong chance you forgot to change it from Outlook too. Here’s a quick guide on how to do it:

Method 5: Check your antivirus scans on outgoing emails

Most antivirus suites perform daily email scanning chores. If a virus is found in your outgoing emails, the antivirus software might prevent it from leaving the outbox until you clean the virus. If you recently got a treat alert, visit your antivirus and dead with any virus treat before trying to send the email again. Also, a lot of antiviruses have the potential to conflict with various versions of Outlook. Generally, antispam plugins of various antiviruses interfere with some Outlook add-ins and may cause the emails to never leave the Outbox folder. Norton and AVG plugins are known to cause problems, but there are definitely others. If you think there’s a conflict caused by one of the antispam plugins, disable email scanning from your antivirus software.

Method 6: Repairing your Outlook program

If you get to this message without a result, your Outlook program might indeed be damaged. Microsoft Outlook is a highly complex program, so you can imagine there can be a lot of problems in a lot of different places. Luckily, Microsoft has an efficient auto-repair method that can be applied to every Office product. The process might take over an hour to complete, so make sure you have enough time on your hands. Here’s what you need to do:

Method 7: Repairing your Outlook profile

In Outlook, a profile holds together a group of settings that govern how the program performs. Among other settings, it includes a listing of all your accounts, auto-complete information, and personal details. If your email messages never leave the outlook folder, repairing your Outlook profile might just fix the issue. Here’s what you need to do:

Method 8: Sending an email in Safe Mode

Now it’s time to find out if anyone of Outlook’s add-ins is crashing, thus preventing your email messages from leaving your outbox. The quickest way to disable all add-ins is to launch Outlook in Safe Mode. If you are able to send emails normally while in Safe mode, it’s clear that one of the add-ins is preventing that from happening. Here’s a quick guide on how to do it:

Method 9: Running the Inbox Repair Tool

Outlook stores your messages and other types of information in a Personal Folders File (PST file). If some information on it becomes corrupted, it might damage some of Outlook functionalities, including the ability to expedite emails from the Outbox folder. However, Microsoft has provided its users with an Inbox Repair Tool capable of repairing PST files. Here’s a quick guide on how to use it:

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