Mail Merge Many-to-One: Combine Rows into One Email

Send one email per recipient that combines multiple spreadsheet rows into a single table. Here's how to set up a many-to-one mail merge in Outlook.

Updated October 2026

Available as a video tutorial

Step 1. Make sure the “To” column in your spreadsheet is identical for all rows you want to group.

Use one row per item, with the same recipient address in the “To” column for every item that belongs in that person’s email. Put column headers in the first row. For example:

Anna will receive one email containing two table rows. Ben will receive one email containing one row. Attachments are optional, not a requirement for many-to-one mode. Curious about why Word can’t merge multiple rows into one email? The knowledge guide explains it.

Step 2. Start a mail merge and upload your spreadsheet

Assuming you have installed SecureMailMerge and started the plugin from the Apps menu, you will see the following screen. Click the “Upload Spreadsheet” button and then select your spreadsheet file from your hard disk.

Step 3. Activate “many-to-one” mode

If there are multiple rows in your spreadsheet with the same email recipient then a message will appear asking you if you would like to send a traditional mail merge or a many-to-one mail merge.

In traditional mail merge mode, each row will be sent as a separate email. In many-to-one mode, all rows with the same email recipient will be grouped together and sent as a single email.

Select “Send one email for multiple rows (many-to-one)”. The “Add many-to-one table to body” button appears under “Compose your message”.

Step 4. Insert the table into your message

Write your email in Outlook and place the cursor where the table should appear. Select “Add many-to-one table to body” in the add-in.

Tick the columns you want recipients to see, for example “Book” and “Due”. Select them in the order you want them to appear. Leave “To” unticked unless the address should be shown in the table. Then select “Add table to Body” and “Return to campaign settings”.

The add-in inserts a table token into your email. When the message is merged, it becomes a table containing that recipient’s rows.

Using ordinary tokens instead of a table

If you insert a regular personalization token (in many-to-one mode) instead of a many-to-one table, values from all rows will be inserted as one long text separated by commas, except for the special columns “Attachments”, “CC”, and “BCC”, which will be combined intelligently (see the next section).

Special note: Combining attachments, CC, and BCC across multiple rows

When using many-to-one mode, SecureMailMerge intelligently combines certain columns across all rows belonging to the same recipient:

• Attachments: All unique attachments from every row are combined into a single email
• CC recipients: All unique CC email addresses are merged together
• BCC recipients: All unique BCC email addresses are merged together

This means you can organize your spreadsheet with multiple rows per recipient, each containing different attachments or CC/BCC recipients, and SecureMailMerge will automatically combine them.

Example: Multiple attachments per recipient

| To                | Attachments           | CC              |
|-------------------|-----------------------|-----------------|
| [email protected]  | contract.pdf          | [email protected]  |
| [email protected]  | invoice.pdf           | [email protected]|
| [email protected]  | terms.pdf             |                 |

Result: John receives one email with all three attachments (contract.pdf, invoice.pdf, terms.pdf) and both CC recipients ([email protected], [email protected]).

Step 5. Send a test email and then send the campaign

You can then proceed by sending a test email, to check your personalization tokens are working as expected.

When you’re happy, you can send the campaign to all recipients.

When the campaign finishes, download the send report before starting another campaign. It keeps one row per original spreadsheet row, even when several rows formed one email.

→ Click here for more help on other use cases (e.g. multiple CC/BCC, personalized attachments etc).