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Office 365

A. Office 365 is the world's most popular SaaS offerings with over 155 million [and growing] users.

It consists of different bundles of Microsoft Office Applications and/or Services, sold as a monthly or annual subscription.

The home version includes the Office applications and OneDrive but no hosted email so cannot be used with the CleanOut for Office 365 app. It does include Outlook so you can use CleanOut for Outlook.

Five of the seven business and enterprise plans include hosted email and can be used with the CleanOut for Office 365 app.

Unlike services like, Yahoo or gmail you can't tell if your email is hosted by Office 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 Office 365 Web Access at If you can then CleanOut for Office 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 Office 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 Office 365 you may have to register your device [with your work or school] for use with Office 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 Office 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 2010, 2013, 2016 or 2019 installed the primary prerequisite is a component called 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 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.

After you have installed VSTO please try reinstalling CleanOut for Outlook.

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 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 G-Suite 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.

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 E-mail(s) - which is/are the emails you have selected in your Inbox or other Incoming Folder
  • New E-mail(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.

As a result, if you have this box unchecked and messages are being scored before the entire conversation has been downloaded 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. 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 and it has not responded. 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.