Knowledge Base


Introduction to CleanOut

A. CleanOut is a productivity app that helps busy people to check their email in a fraction of the time it normally takes. It does this by showing you the most important emails first, helping you understand them and giving you automated workflows to deal with them. In the process, CleanOut ensures that you deal with your most important business first, stay organized and have reminders to follow up on action items.

A. Although some people use CleanOut all day long, it's most effective when you've been away from your email for a while, such as:

  • At the end of a day of back-to-back calls and meetings
  • After being onsite with a client or prospect
  • After a long flight (without access to Wi-Fi)
  • Waking up after your colleagues, in continents to the east, were filling up your inbox
  • Returning from vacation

  1. It’s a complete solution for checking your email. While other solutions focus on a particular aspect of email management such as prioritization, triage, filing or follow-up, CleanOut handles all phases from beginning to end.
  2. It works with Outlook. There are many new email clients or apps which require you to learn how to use a complete replacement for Outlook. CleanOut, on the other hand, is built on the belief that Outlook (including Microsoft 365 and already has all the features you need but power users just need additional help when dealing with massive amounts of email. As a result, CleanOut works with your existing Outlook email, calendar and tasks so you can seamlessly switch back and forth at any time depending on how many messages you have.
  3. Your data stays local. Data security is important to everyone, so it is reassuring to know that with CleanOut your email never leaves your device. Beware of solutions that process your email in some unknown location “in the cloud”.
  4. Its more relaxing. We have enough things to worry about in our busy lives that email shouldn’t be one of them. Opening your email to find a screen full of unread messages is not fun and trying to decide which one is the most important to read first is stressful. CleanOut uses the power of advanced AI to guide you through your most important messages, in priority order, leaving you to decide what action you need to take. The end-result is a much more natural workflow that is more relaxing and less stressful.
  5. It just works. As a busy person you don’t have time for “toy apps” as the decisions you need to make are much more complex than simply deleting newsletters and social media alerts. CleanOut is a powerful tool that gets the job done! It gives insight into your most complex business emails and allows you to go through your email faster than any other solution while still ensuring you don’t miss anything. Try it and we are sure you will agree.

A. For a minimal investment, you should save yourself an hour a day if your currently receive at least fifty (non-spam) messages per day.

Most importantly that hour saved will usually be between 7pm and midnight!

A. Security regarding email is an important topic for any organization so you can rest assured that CleanOut runs 100% locally (i.e. no data leaves your device), and is built upon proven Microsoft standards like Azure AD and Exchange.

The CleanOut apps for Windows and Xbox have been reviewed and certified by Microsoft while the CleanOut for Outlook Add-in is signed with a Extended Validation Certificate, indicating it is safe to install.

A. The good news is that using CleanOut is actually easier than the way you do it today. Just like going from driving a manual transmission car to an automatic, CleanOut automates the process so you can worry about more important things.

Microsoft 365 (aka Office 365)

A. Microsoft 365 (formerly known as Office 365) is a bundle of Microsoft Office Applications and/or Services, sold as a monthly or annual subscription.

All of the bundles include Outlook and can be used with CleanOut for Outlook on Windows desktop BUT not all versions include hosted email which is required for the CleanOut for Microsoft 365 app. The hosted email service is called Microsoft Exchange in the bundles.

A. Unlike services like, Yahoo or gmail you can't tell if your email is hosted by Microsoft 365 by looking at the domain name as you can have any domain you wish [or own].

The easiest way to confirm is by seeing if you can log in to Microsoft 365 Web Access at If you can then CleanOut for Microsoft 365 should work for you.

Note: For security reasons, the OWA link above is not live and you should copy and paste it into your browser.

A. Focused Inbox and Clutter are great new features for the Microsoft 365 users, where it has been enabled, and with CleanOut they are even better. If they’re enabled on a user’s inbox, CleanOut will take into consideration the fact that a message has been classified as Focused or Clutter in determining the importance. CleanOut will also show Clutter messages in its unified Inbox as some people complain that they sometimes miss some important messages that were mistakingly moved to the Clutter folder.

A. The first time you try to access CleanOut for Microsoft 365 you may have to register your device [with your work or school] for use with Microsoft 365.

Please follow the instructions in this article to do this, which you will only need to do once.

A. Unfortunately that is how the underlying interface with Microsoft Exchange currently works so please keep this in mind when deleting messages in CleanOut for Microsoft 365. is a web based email service offered by Microsoft to individuals and small businesses. It replaces previous offerings including Hotmail, Windows Live and MSN email. Click here for more details.

A. Focused Inbox, Sweep and Clutter are great features of for managing personal email. CleanOut builds upon these features and was designed for high volume complex business email with many messages in each thread where you are often required to make decisions [based on the messages]. In fact, CleanOut will take into account that a message has been classified as Focused or Clutter in determining the importance. CleanOut will also show Clutter messages in its unified Inbox as some people complain that they sometimes miss some important messages that were mistakingly moved to the Clutter folder.


A. Besides having Outlook 2013 to 2022 installed, the primary prerequisites are:

  • Visual Studio Tools for Office (VSTO), which is normally installed with Office. If you receive an error message during the installation regarding this module, you can verify if you already have it by looking in Apps and Features for:

    If you do not see it installed, you can download it from here. This will work with all versions of Outlook.

  • Microsoft Edge WebView 2, which is normally installed with Microsoft 365. If you receive an error message during the installation or in OpenMail regarding this module, you can verify if you already have it by looking in Apps and Features for:

    If you do not see it installed, you can download it from here.

After installing either of these modules, try reinstalling CleanOut for Outlook again.

A. In general, you should not need Administrator rights to install or configure CleanOut but if you get these errors messages:

  1. Exit from Outlook
  2. Right click on the Outlook icon on your desktop or start menu and select Run as Administrator and try again. This will temporarily give you the elevated permission you need.

A. This error, which is rare, is usually caused by Outlook not shutting down cleanly which can happen if you close Outlook when it is not responding or has frozen. Be assured that the master copy of your email is on a server and the local .OST file is just a copy that can be repaired or recreated.

To fix this, follow the instructions in this article or seek assistance from your IT help desk.

Follow these same instructions if you have a local PST file that cannot be opened either.

A. This means that the Add-in failed to load while Outlook was starting. To see why it failed to load either:

  • In Outlook go File->Options->Add-ins menu and look for CleanOut in the Inactive or Disabled section. If it is there, click on the Go button at the bottom, find CleanOut in the next list, click on it and look at the message next to Load Behavior. OR
  • From the Run or Search bar in Windows, search for Event Viewer and open it up. In the tree structure on the left hand side click on Application under Windows Logs. In the list of events, scroll up or down and look for recent entries where the source is Outlook and the event ID is 45 or 59. Click on that row and look at the error message that is displayed.

If the error message says:

  • 'Not loaded. A runtime error occurred during the loading of the COM Add-in'. This usually means you have the 64-bit version of CleanOut installed when you need 32-bit or vice versa. Uninstall CleanOut and reinstall the correct version.
  • In Outlook 2013, 2016 or 2019, 'Outlook disabled the following Add-in(s): ... This Add-in caused Outlook to start slowly.' Typically this is caused by Office verifying that the digital signature is still valid [over the internet] and if you have slow internet, it could cause it to take longer than the 1 second threshold. To reinstate CleanOut follow the instructions in this article.

If you encounter other error messages not listed please visit the Customer Care page and report the issue.

A. They are a relatively new type of archive folders that store your filed emails online rather than on your PC as local PST files. See this page for more information.

CleanOut for Outlook supports filing messages in In-Place archives but please be aware they are considerably slower a) opening the Settings dialog and b) Filing messages because, as you would expect, storing emails in the cloud is not as fast as doing it on your hard drive.

So please be patient if using In-Place archives.

A. CleanOut for Outlook has been tested to work with both personal Gmail and business or school Google Workspace (formerly G-Suite) email accounts.

If you have a personal Gmail account click here to learn how to enable IMAP so you can use it with Outlook.

If you have a Google Workspace email account (most likely with your company or school's domain) click here to learn how to sync your G-Suite email, calendar and tasks with Outlook.

Once you have configured your Gmail or G-Suite account to work with Outlook, you can start using it with CleanOut like any other type of email account.


A. A key feature of CleanOut is the ability to present your message in order of importance. Behind the scenes, it does this by assigning a score between 1 and 1,000 to every message based on its predicted importance to you.

Scoring, therefore, is the process of assigning scores to your emails.

If you are curious, you can see the Scores assigned to your email by:

  • Right clicking on one of the headings in your Inbox (such as Subject or Received)
  • Select Field Chooser
  • In the drop down box, scroll to the bottom and select 'User Defined Fields in Inbox'
  • Click on the Score box and drag it to where you want it to appear in the heading. To the right of the Size column is a good place.

A. Your messages are scored in two ways:

1. Automatically as they are received in one of your Incoming Folders.

2. Manually by using the Score icon on the Lucky Duck ribbon, where you have the option to Score:

  • Selected email(s) - which is/are the emails you have selected in your Inbox or other Incoming Folder
  • New email(s) - which are all unscored emails in the last two weeks
  • All e-mail(s) - which means all emails in your Incoming Folder

(The Quick Score check box tells CleanOut not to look inside the email body or text which makes it a lot faster)

When you start CleanOut for the first time you are encouraged to just score the New E-Mail(s). From that point forward all of your new emails will be scored automatically unless you notice that a message or messages did not get scored for some reason, in which case you can click on the Score icon to do it manually.

When you have time, though, it is a good idea to score all emails so that you can use the date range filter to see older messages. Note that this might take a while if you have a lot of messages in your Inbox (say > 10,000) so you may want to do this over lunch or while you will be in a meeting as your PC will be tied up for this time. If you have a slow Internet connection, you may also put Outlook in offline mode, by clicking on Send/Receive->Work Offline, to make it go faster.

A. When Outlook has not been running for a while and you turn it back on, new messages are downloaded in no particular order which means that messages could be scored before the rest of the conversation has been downloaded. As a result, the scoring will not be as accurate as CleanOut doesn't have the entire context.

If you select this option and have slow Internet you will have to be patient, before you Open your mail, as it can take a minute or more to download all messages and sync the offline address book (which Outlook does by default).

A. Users that often receive thousands of emails between Outlook sessions may want to uncheck this option to avoid delays when Outlooks starts.

It means, however, that they will have to score your messages manually (using the Score Mail option from the Lucky Duck ribbon) when convenient.

A better solution is to leave Outlook running so messages are scored as they are received.

A. CleanOut single threads all scoring requests to avoid conflicts. This message means your request is waiting on another to finish.

If it sits there for a minute or two without scoring, close the dialog by clicking on the X button, close Outlook and restart to clear out the queue.

A. If you see the progress bar and message information 'freeze' it is because CleanOut is waiting for Exchange to return some information. The default timeout period is 30 seconds which is why you are seeing the pause.

Putting Outlook in offline mode before starting the scoring process will reduce the number of timeouts but may not eliminate them completely.