# Mail Merge in Outlook on the Web (Outlook 365 Online)

> Mail merge in Outlook on the web: why Word's merge sends nothing, what the built-in option does, and how to send personalized Excel emails in the browser.

You can do a mail merge in Outlook on the web, but not from Word. Word's merge sends through a desktop Outlook (classic Outlook on Windows or Outlook for Mac), and the browser can't receive it. Outlook's built-in mail merge sends everyone a separate copy of the same text, with no spreadsheet fields. For personalized emails from Excel in Outlook online, use an add-in such as SecureMailMerge.

Outlook on the web, Outlook online, Outlook 365 online and OWA in Microsoft 365 are different names for the same browser app at outlook.office.com, so everything here applies whichever name your organization uses. For the bigger picture, see the [full guide to mail merge in Outlook](https://www.securemailmerge.com/mail-merge-outlook/).

## Word's mail merge doesn't work in the browser

Word's mail merge can't send on its own. It needs classic Outlook on Windows or Outlook for Mac installed on your computer. If you only use Outlook in a browser or in New Outlook, nothing is sent. More on New Outlook in [mail merge in New Outlook](https://www.securemailmerge.com/help/mail-merge-for-new-outlook/).

## The built-in mail merge isn't really a mail merge

New Outlook has a "Start mail merge" option, under the arrow next to "Send" in a new message, and Outlook on the web may show it too. It gives each recipient their own copy, so nobody sees the other addresses, but that is all it does. There are no fields from a spreadsheet, so everyone reads the same text, and there is no import from Excel and no per-recipient attachments, CC or BCC. Fine for a plain announcement, not for "Hi Anna, invoice INV-101 is attached". For Excel fields in a browser or in New Outlook, you need an add-in inside Outlook.

{/* VERIFY: Microsoft documents "Start mail merge" for New Outlook only; web parity comes from our New Outlook help page and third-party guides, not tested in Outlook on the web directly. */}

Classic Outlook on Windows or Outlook for Mac installed: Word's merge works. Same text to everyone: the built-in merge. Excel fields in the browser or in New Outlook: an add-in inside Outlook.

## How to do an Excel mail merge in Outlook on the web

SecureMailMerge adds a mail merge panel to the compose window in Outlook on the web. It reads your Excel or CSV file and sends one email per row from your own mailbox, with copies in Sent Items. Nothing to install on your computer, no Word involved, and on a Mac it is the same add-in in Outlook for Mac.

### Step 1: Sign in with a work or school account

Open outlook.office.com and sign in with your Microsoft 365 Business or Education account. Personal Outlook.com, Hotmail and Microsoft 365 Personal or Family accounts can't run the add-in; see [supported accounts](https://www.securemailmerge.com/help/personal-accounts/).

### Step 2: Install SecureMailMerge from the Apps menu

Click "New mail", open "Apps" on the "Message" tab, choose "Add apps", search for SecureMailMerge and select "Add". You can also install it from the [Microsoft AppSource listing](https://www.securemailmerge.com/store). If you see "Need admin approval", your IT admin must approve it first. All methods are in the [installation guide](https://www.securemailmerge.com/help/installation/).

![Outlook on the web compose window with the Apps menu open, showing SecureMailMerge and the Add apps button](https://www.securemailmerge.com/screenshots/start-addin-outlook-web-2024.png)

### Step 3: Prepare your spreadsheet with a To column

Put column names in the first row and email addresses in a column called "To", one row per recipient. Add a column for anything you want to personalize, such as FirstName, Company or InvoiceNumber. Give every column a name in the first row. Columns without a name are ignored, and rows without an address in the To column are skipped.

### Step 4: Upload the spreadsheet in the add-in

Start a new email, open "Apps" and choose SecureMailMerge. Click "Use spreadsheet" and select your Excel or CSV file. Check that the number of records matches your list, and [unselect anyone you want to skip](https://www.securemailmerge.com/help/reviewing-and-unselecting-recipients/).

![The Upload spreadsheet step in the SecureMailMerge panel](https://www.securemailmerge.com/screenshots/upload-spreadsheet.png)

### Step 5: Write your message with merge fields

Write the subject and body as usual. Pick a column from the dropdown and click "Add to body" or "Add to subject" to insert a field such as `{{FirstName}}`, and each recipient sees their own value. For cells that may be empty, add a fallback like `{{ FirstName | default: 'there' }}`. More in [creating your mail merge email](https://www.securemailmerge.com/help/creating-a-mail-merge-template/).

### Step 6: Send a test, then start the campaign

Click "Send test email to yourself" to get the first selected recipient's email in your own inbox and check fields, links and attachments. Then, in the "Send campaign" step, click "Start sending campaign". Keep the message window open while it generates messages, or pop the email out into its own window. When it finishes, [download the send report](https://www.securemailmerge.com/help/downloading-the-send-report/).

![The Send campaign step with the Start sending campaign button](https://www.securemailmerge.com/screenshots/start-sending-campaign.png)

## For admins: deploy it once for everyone

If users see "Need admin approval", or you want everyone to have the add-in without installing it, deploy it from the Microsoft 365 admin center under "Settings" > "Integrated apps". Microsoft says a deployed add-in can take up to 72 hours to appear. Instructions: [deploy SecureMailMerge to your organization](https://www.securemailmerge.com/help/centralized-deployment/). To approve the permissions without deploying, see [why you see "Need Admin Approval"](https://www.securemailmerge.com/help/need-admin-approval/).

## Word merge vs built-in merge vs SecureMailMerge

| Capability | Word mail merge | Built-in mail merge (web) | SecureMailMerge |
|---|---|---|---|
| Runs in the browser | No, needs desktop Word and desktop Outlook | Yes | Yes |
| Per-recipient fields from Excel or CSV | Yes | No | Yes |
| Per-recipient attachments, CC, BCC | No | No | Yes |
| Test email | Preview in Word | No | "Send test email to yourself" |
| Cost | Included with desktop Word | Included with Microsoft 365 | Free with a promotional footer, [paid license](https://www.securemailmerge.com/pricing/) removes it |

## Privacy and sending limits

Your spreadsheet, message and attachments are processed inside Outlook and sent through your own Microsoft 365 mailbox; only the licence check (your mailbox address, product name and a timestamp) goes to the licensing server. Details in the [IT security documentation](https://www.securemailmerge.com/trust/security/). Sending uses the same Microsoft 365 limits as any other Outlook, and for large lists you can tick "Limit how many are sent each day" in the advanced options. The numbers are in [Outlook email sending limits](https://www.securemailmerge.com/knowledge/outlook-email-sending-limits/).

## Frequently asked questions

### Can I do a mail merge in Outlook on the web?

Yes, with an add-in. The built-in mail merge in Outlook online sends separate copies of the same text. For fields from Excel, such as names or invoice numbers, use an add-in like SecureMailMerge, which runs inside Outlook on the web.

### Why does Word's mail merge send nothing when I use Outlook in the browser?

Word hands the finished emails to a desktop Outlook (classic Outlook on Windows or Outlook for Mac), and Outlook in the browser can't receive them. If no desktop Outlook is installed, nothing is sent. If one is, check its Outbox.

### Does it work with Outlook.com personal accounts?

No. SecureMailMerge needs a Microsoft 365 Business or Education mailbox, so Outlook.com, Hotmail and Microsoft 365 Personal or Family accounts can't run it.

### Do I need my IT admin to install it?

Only if your organization requires approval. If you see "Need admin approval" or "Approval required", an admin can approve the permissions or deploy SecureMailMerge to everyone from "Integrated apps" in the Microsoft 365 admin center.

### Is there a free version?

Yes. The free version includes every feature and adds a short promotional footer to each email. A paid license removes the footer. Prices vary by country, so check the pricing page.

## Related guides

- [Mail merge in Outlook: the complete guide](https://www.securemailmerge.com/mail-merge-outlook/)
- [Mail merge in New Outlook](https://www.securemailmerge.com/help/mail-merge-for-new-outlook/)
- [Install SecureMailMerge](https://www.securemailmerge.com/help/installation/)
- [Send a different attachment to each person](https://www.securemailmerge.com/help/sending-mail-merge-with-individual-attachments/)
- [Add CC or BCC recipients to a mail merge](https://www.securemailmerge.com/help/add-multiple-cc-or-bcc-recipients-to-a-mail-merge/)
- [Send a mass email individually in Outlook](https://www.securemailmerge.com/knowledge/send-mass-email-individually-outlook/)