Google Drive can store files and attach them to emails, but it is not the only option. Let’s see how to integrate other cloud storage services with Gmail. Use Dropbox with Gmail, and Box too.
Box and Dropbox are two excellent alternatives to Google Drive for storing files and some businesses prefer them. If you or your company is a Box or Dropbox user, you can use it instead of Google Drive to store files, attach them to emails, and save attachments from emails in your Gmail inbox.
One way to send someone a file using email is to visit the Dropbox or Box site, find the file, get a link, switch to Gmail, and paste the link into the email. If you want to save an email attachment to Dropbox or Box, it can be saved to disk and then moved from the Downloads folder to a sync folder or uploaded to online storage using a browser.
Integrate Box and Dropbox with Gmail and both processes are a lot simpler. You can save email attachments directly from Gmail to Box or Dropbox, and you can attach documents and other files to emails from within Gmail when writing an email.
There are free and paid accounts for Box and Dropbox and here I use free accounts. A subscription is not required. Let’s see how to integrate Box and Dropbox with Gmail.
Install Dropbox and Box add-ons in Gmail
1: Gmail add-ons

Go to Gmail in a web browser and click the gear icon in the top right corner. When the quick settings panel opens on the right, go to all settings and then select the Add-ons tab. Add-ons are listed if you have any. Click the Manage link.
2: View, find, browse Gmail add-ons

A window appears that lists installed add-ons. It is mostly empty if you do not have any. The easiest way to find Dropbox and Box add-ons is to click the search icon and search for them.
An alternative is to click the menu button and browse the categories of add-ons. Dropbox and Box can be found in the top and most popular add-ons lists.
3: Install Box add-on in Gmail

When you find the Box add-on for Gmail, click it to open the details view and then click the Install button. After installing an add-on, the button becomes Uninstall, so if you ever need to remove it, just return here.
4: Install Dropbox add-on in Gmail

Find and install the add-on to use Dropbox with Gmail. When searching for useful add-ons, look at the star rating and the number of downloads. The best add-ons have a high rating and many downloads.
5: Access add-ons in Gmail

Add-ons installed in Gmail appear in the sidebar on the right-hand side of the inbox. If this panel is not visible, click the > button in the bottom right corner of the page. The top few icons are built in, like Calendar and Keep, and the ones you add are at the bottom of the list.
Add-ons are installed in Gmail, which is a web-based service. This means that if you install them on one computer, they appear on all computers that you use.
Security and permissions
I won’t go into this because it is so boring. I will just say that there are lots of permissions required on both sides. Gmail needs permission to access Dropbox and Box files and Dropbox and Box need permission to access Gmail.
Agree to all the permissions when prompted. Use both Box and Dropbox at least once before using them for real. The first use triggers more permissions and it gives you the opportunity to log into your accounts.
Once you have the add-ons working, continue…
Save email attachments in Gmail
6: Save email attachments to Dropbox

Open an email that has one or more file attachments. Click the Dropbox icon in the right-hand sidebar to open the Dropbox panel on the right.
The email attachment is automatically listed and it shows the filename and date. Click it.
7: Browse Dropbox and save attachments

Click the file attachment and Dropbox shows the folders in your online storage. Click any of the folders to open them and find the place you want to save the attachment to. Click the SAVE button to save it to the selected folder.
8: Close the panel

The email attachment has been successfully saved to Dropbox online and the panel can now be closed by clicking the cross button in the top right corner.
9: Save email attachments to Box

Saving email attachments to Box online storage is very similar, but there are a couple of extra options. Click the Box icon in the sidebar and a list of attachments with checkboxes appears. You can choose which ones to save. Click SAVE ATTACHMENTS and select the folder to save them to.
Another useful option is to save the email as a text file. It could be useful to save it with the files, then you will not forget what they are or where they came from.
Attach Dropbox and Box files to emails in Gmail
10: Box and Dropbox in the email editor

Create a new email or reply to an email and the email editor popup window appears in the corner of Gmail. After the usual Gmail icon are your add-ons and this is where to find Box and Dropbox. They can be used to attach files to emails in the same way as Google Drive. Click an icon.
11: Browse files and attach them to emails

Click the Box or Dropbox icon in the email editor and a window opens to enable you to browse the files in your online storage. Click folders to open them and click a file to add it to the email.
12: Send emails with attachment links

The selected file is added to the email as a link. The file itself is not inserted, which means that the size of it does not matter. It can be huge because all you are sending is a link.
When the email recipient receives the email, they click the link to access the file.
I found a minor annoyance with Dropbox here, which makes it not quite perfect. When the recipient of the email clicks the attachment, Dropbox opens in a tab and a Sign In/Sign Up popup window appears on the screen.
It makes it look like you cannot save the email attachment unless you do one or the other. Click the cross to close the popup and you can download the file. It might be worth adding a brief note in the email telling the person they can skip sign-in/sign-up.
Box is very similar, except that when a file is selected as an attachment in Gmail, there are three link permissions to choose from: People with the link, People in the company, and People in this folder/file. These are useful for limiting who can access the file and they help prevent links from being shared by the recipient of the email. For this reason, I prefer Box as a Google Drive alternative, at least when it comes to working with Gmail.