What is the best way to mail merge in Outlook?

It depends on one question: does every recipient need a different attachment? If not, Word's built-in mail merge is free, already installed and perfectly good. If they do, Word cannot do it at all, and the realistic options are a VBA macro, an Outlook add-in, or a bulk email platform.

Is there a free Outlook mail merge tool?

Two free routes exist. Word's mail merge is built into Office and handles personalised message text well, but cannot vary the attachment per recipient. A VBA macro can vary the attachment and costs nothing, but runs only in Outlook on Windows, is frequently blocked by IT policy in managed organisations, and usually sends without a preview.

Do I need a bulk email platform to send personalised documents?

Usually not, and often it is the wrong fit. Platforms built for newsletters send through their own infrastructure, which means configuring SPF and DKIM for a new sender, a separate sending reputation from your ordinary correspondence, and replies arriving somewhere other than your mailbox. For invoices, payslips and similar documents, sending from the mailbox that normally sends them is simpler and behaves better.

Does Outlook mail merge work on Mac?

The Word-to-Outlook route is unreliable outside Outlook on Windows, and VBA macros do not exist on Mac or on Outlook on the web at all. Modern Outlook add-ins are built on web technology, so they run in Outlook on Windows, Mac and the browser — which is usually the deciding factor for anyone not on Windows.

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Best Outlook mail merge tools

We make one of these, so treat this as informed rather than neutral. It is still worth reading: two of the four options are free, and for a lot of people one of those is the right answer.

Answer this first and most of the choice disappears.

Does every recipient need a different file attached? If no — you are sending the same newsletter or the same notice to everyone — Word's mail merge already does what you need, free, and you can stop reading. If yes, Word cannot do it at all, and the remaining three options are what this page is about.

1. Word's built-in mail merge — free

Already on your machine, well documented, and genuinely good at what it was built for: personalising the text of a message from a spreadsheet.

Its limit is specific rather than general. The merge has no attachment field, because it was designed for printed letters, and that was never added when Microsoft wired it to email. So every recipient gets the same attachment or none. More on where Word stops.

Choose it when: the attachment is the same for everyone, or there is no attachment.

2. A VBA macro — free

The traditional workaround. A macro reads your spreadsheet, attaches the file named in each row, and sends. It genuinely works, and it costs nothing but your time.

Three things decide whether it is viable for you:

Windows only. VBA does not exist in Outlook on Mac or on the web.
Often blocked. Managed organisations routinely disable macros, and getting an exception for a script from a forum is rarely a quick conversation.
Usually no preview. Most macros send straight from the loop, so a wrongly mapped column is discovered by your recipients.

Choose it when: you are on Windows, macros are permitted, and you are comfortable reading the code you are about to run against your own mailbox.

3. An Outlook add-in — paid

Add-ins put the merge inside Outlook. The good ones read a filename column, match it against a folder, preview each assembled message, and send from your own mailbox so replies come back to you and a copy files itself in Sent Items.

There is more than one, and they differ in ways worth checking before you buy — see the questions below. Tellmerge is ours: one-time price per mailbox, runs in Outlook on Windows, Mac and the web, previews every message, and refuses to send a row whose attachment is missing.

Choose one when: attachments vary per recipient and you would rather check the result than hope.

4. A bulk email platform — subscription

Mailchimp, Brevo and similar. Built for newsletters, and excellent at that: list management, unsubscribes, open rates, scheduling.

They fit business documents badly. Mail leaves through the platform's infrastructure, so it needs SPF and DKIM set up for a new sender, sits in a different reputation pool from your ordinary correspondence, and replies go to the platform. An invoice is correspondence, not a campaign, and it is better sent from the mailbox that already sends your correspondence. How delivery actually works.

Choose one when: you genuinely are sending marketing, and need unsubscribes and analytics.

The questions that separate the paid add-ins

Whichever you look at, including ours, these are worth answering before paying:

Where does it run? A desktop COM add-in means Windows. A web-based add-in runs on Windows, Mac and the browser. This is usually the deciding constraint.
What happens to a row whose file is missing? Sending an invoice email with no invoice is worse than not sending. It should be held back and named.
Can you see the messages before they go? Merge errors are systematic — a wrong column is wrong for everyone at once.
Who sends the mail? Your mailbox, or the vendor's servers? That determines your Sent Items, where replies land, and whose reputation carries the mail.
One-time or subscription? Both exist. Neither is wrong; just know which you bought.

Accurate as of 2026, and deliberately light on specifics.

Prices and feature lists change, and a comparison table that quietly goes stale is worse than none. The structural differences above — where the software runs, who sends the mail — change rarely. Check the current details on each vendor's own site before you buy.

More comparisons · How per-recipient attachments work · Tellmerge pricing