How to attach Explorer folders to Outlook emails?

by | Feb 24, 2022 | How-to's

How to attach Windows Explorer folders to Outlook emails doing a drag and drop.

Attaching Explorer folders is not supported by MS Outlook.

When trying to attach a folder to an Outlook email, you get this:

Explorer folders cannot be dropped to an Outlook email.

Yes this is right, but this was before Attach2Cloud!

Thanks to Attach2Cloud, you can now drag and drop Explorer folders to your Outlook emails!

Now, you are probably wondering what happens when dragging and dropping a folder to Outlook.

Well, let’s have a look together.
Let’s start with a simple case, a folder with 3 files:

Let's attach (drag and drop) a folder with 3 files to our Outlook email.

Dragging and dropping a folder to an Outlook email.

Let’s create a new email and simply drag and drop this folder to our email:

The dropped folder is automatically compressed into a Zip file...

The dropped folder is accepted by Outlook with no question asked, and is attached to our email as a Zip file:

And the resulting Zip file is then attached to our Outlook email.

OK, this was with a small folder.

Now, what about a 1 GB folder with more than 3,000 files?

No problem, see, we have one. Let’s try to drag and drop it to our email:

Now, let's try with a large folder containing more than 3000 files and folders.

Dragging and dropping a very large (1 GB) folder to an Outlook email.

Let’s drag and drop this 1 GB file to our email.

A friendly confirmation dialog is displayed:

A friendly (configurable) warning informs us that the size of the folder dropped into our Outlook email is over 150 MB.

(This Attach2Cloud dialog is optional and the number of MB  triggering it is configurable).

Once this dialog validated, the dropped folder and its 3,000 files and folders are automatically compressed into a Zip file: 

The folder is then compressed into a Zip file.

And the Zip file is then attached to our email:

The compressed Zip folder is then attached to our Outlook email.

You can also drag and drop several folders, as well as any combination of files and folders to your Outlook emails at the same time, in a single drag and drop operation.

How can this very large Zip file (several hundreds of MB) be attached to an Outlook email?

Well, this is the Attach2cloud magic at work.
Did you notice this little picto added to the attached file icon?

How can such a large file be attached to an Outlook email?

This means that attaching this file would result in exceeding the Outlook maximum allowed email size.

Without Attach2cloud, this file could not be attached to our email.
We would have gotten this error when attaching it:

The file you're attaching is bigger than the server allows. Try putting the file in a shared location and sending a link instead.

But, thanks to Attach2Cloud, Outlook did not raise any error when this file was attached to your email.

Of course, there is a trick here:

This very large Zip file is apparently attached to your email but in fact it is not.
The attached Zip file you see in your Outlook email is in fact a placeholder (see the size of he file mentioned in the email attached file icon is 1 KB).
Attach2Cloud will upload (automatically) this very large attached file to OneDrive when you send your email and will replace its current placeholder icon it by a OneDrive shortcut before the email is sent.

Let’s click on Send to see what exactly happens when sending this email. 

At the time you click on Send, Attach2Cloud displays the “Attached File Control Center”.

The Attached File Control Center lists the files attached to the email being sent and enables you to upload the attached files of your choice to OneDrive (simply check the files to upload). 

The Attach2Cloud Attached File Control Center gives you the full control on the upload of your Outlook attached files to OneDrive

Depending on Attach2Cloud settings (rules), all files can be checked by default, or only files exceeding a given file size or only files of given file types etc.
Displaying the Attached File Control center is optional. If it is not displayed, Attach2Cloud will automatically upload to OneDrive the files targeted by the rules you specified (without displaying any dialog after you click on Send).

As you can see in the above screenshot, our large Zip file (981 MB) resulting of the compression of our 1.4 GB folder is checked and will be uploaded to OneDrive.
If we try to uncheck it, Attach2Cloud warns us: 

Large files exceeding the Outlook maximum allowed email size limit must be uploaded to OneDrive.

And if, despite this warning, we try to validate the Attached File Control Center window without checking at least our largest attached file, Attach2Cloud prevents us to send our email: 

A warning explains why you have to upload your large files to OneDrive.

Let’s check both files then click OK.

All the attached files of this Outlook email are checked for upload to OneDrive.

Our email is put in the Outlook Outbox, like any other email to be sent.
Et voilà!
Attach2Cloud then uploads the attached files to OneDrive, shares them with the email recipients and replaces them with OneDrive shortcuts in the email being sent.
Once these operations are completed, Outlook sends the email containing the OneDrive shortcuts to its recipients. All this is 100% automatic.

Please have a look at these pages for more details bout these operations:

Try for Yourself!

Enjoy sending Multi-Gigabyte Outlook emails to your colleagues and friends, Download a free fully functional evaluation copy of Attach2Cloud for Outlook and OneDrive.
It takes less than one minute to install.

Then see for yourself how easy it is to send extra-large (or not) files and folders as Outlook attached files, thanks to Attach2Cloud:
Once Attach2cloud is installed, start Outlook, create a new email, attach some files and/or folders (large or not) to it and send it. That’s it. You have nothing special to do!

Attach2cloud works with any 32-bit or 64-bit version of Outlook 2013, Outlook 2016 and Outlook 2019 running on Windows 7, Windows 8.1 or Windows 10, and OneDrive for Business (the version of OneDrive available through Office 365 subscriptions).

In case you are using Outlook but, for any reason, not using OneDrive for Business, we have other solutions like Z-OptimiZr for Microsoft Outlook and ZipMail Real-Time for MS Exchange Server to help reducing the size of your Outlook emails.

Some questions about Attach2Cloud?

For a more complete description of Attach2cloud, please see the Attach2Cloud home page and the Attach2cloud Usage Cases page.

Please also have a look at the Attach2Cloud Q&A page and don’t hesitate to contact us, we’ll always be most pleased to answer any questions you may have about Attach2Cloud.

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Last updated: Febr 2, 2023