What a mail merge does and why you'd use it

A mail merge takes a list of names, email addresses, and other details — stored in a spreadsheet or database — and automatically fills them into an email template you write once. Instead of typing "Dear John" in one email and "Dear Sarah" in another, you write "Dear [FirstName]" once, and Outlook sends a personalized version to each person on your list.

The most common use is sending the same message to many people with each person's name, company, or other details customized in the body. You might use this to send a price quote to ten clients with each one's company name inserted, or a meeting reminder to a team where each person sees their own start time.

Outlook does not have a built-in mail merge feature the way Word does. Instead, you prepare your data and template in Word, and Word handles the merge while sending through Outlook. This means you need both programs open and working together.

Key Takeaways

  • Mail merge in Outlook requires you to create the template in Word, not in Outlook itself, because Word contains the merge tool.
  • Your contact list must be in a spreadsheet (Excel) or a database format, with column headers in the first row and one person per row below.
  • You insert merge fields like [FirstName] and [Company] into your Word template, then Word sends the merged emails through Outlook automatically.
  • The merge sends emails from your Outlook account, so you must be logged in and your account must have permission to send on your behalf.

Prepare your contact list in Excel

Open Excel and create a new spreadsheet. In the first row, type the column headers — these are the names of the fields you will insert into your email. Common headers are FirstName, LastName, Company, Email, Phone, or any other detail you want to personalize. Type each header in its own cell across the top row.

Below the headers, enter one person per row. Put their first name in the FirstName column, their email address in the Email column, and so on. Make sure every person has an email address filled in — if a row is missing an email, Word will skip that row during the merge and no email will be sent to that person.

Save this file with a clear name like "MailMergeContacts.xlsx" in a folder you can find easily. Do not close Excel yet — you will need to reference this file when you set up the merge in Word.

Create your email template in Word

Open a new Word document. Type the email you want to send. Write it as if you are sending it to one person, but use merge field placeholders where you want personalized details to appear. For example, instead of typing a specific name, type "Dear [FirstName]," or "Hi [FirstName] at [Company],". The text inside the square brackets must match your column headers exactly — if your Excel column says "FirstName", use [FirstName], not [First Name] or [firstname].

Write the rest of the email body normally. You can include multiple merge fields in the same sentence or paragraph. For example: "We have a special offer for [Company] this month, [FirstName]. Your account number is [AccountNumber]." When the merge runs, each copy will have the actual values from that row of your spreadsheet.

Do not add a subject line in Word — you will set that in Outlook after the merge starts. Save this document with a clear name like "EmailTemplate.docx".

Start the mail merge in Word

With your template document open in Word, go to the Mailings tab at the top of the ribbon. Click Start Mail Merge, then select E-mail Messages from the dropdown. This tells Word you are merging to email, not to letters or labels.

Next, click Select Recipients and choose Use an Existing List. A file browser will open. Navigate to the Excel file you created earlier and select it. Word will ask you which sheet contains your data — if you only have one sheet, it will be selected already. Click OK.

Word will now show your template with the merge fields still visible. You can see them highlighted in gray. If a field is not highlighted, click on it and Word will recognize it. This is your chance to review the template and make sure the merge fields are in the right places before you send anything.

Insert merge fields into your template

If you need to add a merge field after you have already started the merge, position your cursor where you want the field to go. Click Insert Merge Field in the Mailings tab, and a dropdown will show all the column headers from your Excel file. Click the one you want to insert.

Word will insert the field name in square brackets, like [FirstName]. This is the correct format. Do not type the brackets and field name by hand — always use the Insert Merge Field button, because Word needs to recognize the field as a merge field, not just text that looks like one.

After you insert a field, you can type normally around it. You can add punctuation, spaces, or other text right next to the merge field without any special formatting.

Preview the merge to check for errors

Before you send any emails, click Preview Results in the Mailings tab. Word will show you what the first email will look like with actual data from your spreadsheet filled in. The merge fields will disappear and you will see real names, companies, or other details in their place.

Use the arrow buttons next to Preview Results to scroll through several examples and make sure the data looks correct. Check that names are spelled right, that company names match what you expect, and that the email reads naturally with the personalized details included. If something looks wrong — a misspelled name in your Excel file, or a merge field in the wrong place — go back and fix it now before you send.

Click Preview Results again to turn off the preview and return to seeing the merge field names.

Send the merged emails through Outlook

In the Mailings tab, click Finish & Merge, then select Send E-mail Messages. A dialog box will appear asking you to fill in the email details. In the To field, click the dropdown and select the column name that contains email addresses — usually "Email".

In the Subject line field, type the subject line you want all emails to have. Unlike the body, the subject line does not merge — every email will have the same subject. If you want the subject to be personalized too, you would need to set that up differently, but for most uses a single subject line works fine.

Leave the other fields blank unless you have a specific reason to change them. Click OK, and Word will send one email to each person on your list. Outlook will open in the background and handle the sending. Depending on how many emails you are sending, this may take a few seconds to a few minutes.

Troubleshooting common problems

If Word says it cannot find your Excel file, make sure the file is saved and closed. Word needs to read the file, and some versions have trouble if Excel has it open at the same time. Close Excel, then try the merge again.

If some emails do not send, check that every row in your Excel file has an email address in the Email column. Word skips rows with missing email addresses silently — it will not warn you. Open your Excel file, scan the Email column, and fill in any blanks.

If the merge fields show up in the email body instead of being replaced with actual data, the field names in your template do not match your column headers exactly. Check for extra spaces, different capitalization, or typos. Delete the incorrect field and use Insert Merge Field to add the correct one.

If Outlook does not open or the emails do not send, make sure you are logged into Outlook and that your account is set up to send mail. Try sending a regular email from Outlook first to confirm it is working. Then go back to Word and try the merge again.

Frequently Asked Questions

Can I personalize the subject line too, not just the body?

Yes, but it requires a different approach. Instead of using Finish & Merge, use Finish & Merge > Merge to New Document to create individual emails as a Word document. Then copy and paste each one into Outlook manually, or use a third-party tool designed for subject line merging. For most uses, a single subject line is simpler and works fine.

What if I only want to send to some people on my list, not everyone?

After you select your recipients, click Edit Recipient List in the Mailings tab. A dialog will open showing all your contacts. Uncheck the boxes next to anyone you do not want to email. Only the checked names will receive emails when you finish the merge.

Can I use a Word table instead of an Excel file?

Yes. Create a table in Word with your column headers in the first row and your contact data below. Save the document, then in the mail merge, select Use an Existing List and choose that Word document. Word will recognize the table as your data source.

Will the recipients see each other's email addresses?

No. Each person receives their own individual email sent to their address alone. The merge sends separate emails, not a group email, so no one sees the other recipients' addresses or knows who else received the message.

What happens if I close Word before the merge finishes sending?

If you close Word while Outlook is still sending, Outlook will continue sending the remaining emails in the background. You do not need to keep Word open once the send process has started. Check your Outlook Sent folder after a few minutes to confirm all emails went out.