🔒 Your email never leaves your mailbox

From one spreadsheet to hundreds of personal emails

Personalized bulk email with a different attachment for every recipient — invoices, offer letters, certificates — sent straight from your own Microsoft 365 mailbox.

New Outlook for Windows Outlook for Mac Outlook on the web
recipients.csv
NameAttachment
Alice Wong📎 alice_invoice.pdf
Ben Ortiz📎 ben_invoice.pdf
Chen Li📎 chen_invoice.pdf
To Alice Wong — “Your March invoice”
📎 alice_invoice.pdf
To Ben Ortiz — “Your March invoice”
📎 ben_invoice.pdf
To Chen Li — “Your March invoice”
📎 chen_invoice.pdf
Built for recruiters, fundraisers & small teams
What makes it different

The mail merge native Outlook can’t do

Word mail merge can’t attach a different file per person. Old add-ins are Windows-only and breaking in new Outlook. MergeBird fixes both — on every device.

⭐ The hero feature

A different attachment for every recipient

Add a column with each person’s file name, upload the files, and MergeBird matches them automatically — so everyone gets their own document, not a shared one.

  • Auto-matched by filename from your spreadsheet
  • Invoices, offer letters, certificates, donation receipts
  • See exactly how many matched before you send
Attach files
Alice Wong📎 alice_invoice.pdf
Ben Ortiz📎 ben_invoice.pdf
Chen Li📎 chen_invoice.pdf
✓ 42 of 42 files matched

Privacy-first

Messages send straight from your Microsoft 365 mailbox. We never see, store, or route your subjects, bodies, recipients, or attachments.

Truly cross-platform

Built on the modern Office Add-ins platform — runs in new Outlook on Windows, Mac, and the web. No desktop-only lock-in.

Real personalization

{{first_name}} tokens with fallbacks in the subject and body. Import from CSV/Excel or paste a table.

Send responsibly

Smart pacing respects Microsoft’s limits, with a dry-run mode, resumable sends, an unsubscribe footer, and a suppression list.

Preview everything

See exactly what each recipient gets — merged subject, body, and attachment — before a single email goes out.

Replies come to you

Because it sends from your real mailbox, replies land in your inbox and your sends look 100% human — not blasted from a relay.

Three steps

From spreadsheet to sent in minutes

1

Write & import

Compose your template with personalization tokens, then drop in your CSV/Excel of recipients.

2

Attach & preview

Match a file to each recipient, then preview the exact message anyone will receive.

3

Send from your mailbox

MergeBird sends each one individually, paced and resumable. Check Sent Items — it’s all there.

Pricing

Start free. Upgrade when you scale.

No subscription required — grab a credit pack if you only send now and then.

Free

$0
forever
  • 50 personalized sends / month
  • Personalization tokens
  • Shared attachments
  • Preview & dry-run
Get started

Credit pack

$19
one-time · never expires
  • 500 extra sends
  • All Pro features
  • No subscription
  • Great for one-off campaigns
Buy credits
FAQ

Questions, answered

Does my email really stay private? +

Yes. MergeBird sends through Microsoft’s own APIs from your mailbox. Your message content, recipients, and attachments never touch our servers — we only ever record an anonymous send count for your plan.

Does it work on Mac? +

Yes — new Outlook for Mac, Windows, and the web. That cross-platform support is a core reason MergeBird exists; most old mail-merge tools are Windows-only.

How are per-recipient attachments matched? +

Add a column with each row’s file name, upload the files, and MergeBird matches them by name automatically — showing you how many matched before you send.

Will I hit Outlook’s sending limits? +

MergeBird paces sends to stay within Microsoft’s limits and shows progress as it goes. It’s built for personalized, moderate-volume campaigns — not spam blasts.

My old mail merge broke in new Outlook. Will this help? +

That’s exactly why we built it. Microsoft’s new Outlook drops the old COM/VSTO add-ins — MergeBird runs on the modern platform that new Outlook supports, on every device.

Get MergeBird for Outlook

Free for your first 50 personalized sends every month. Coming soon to Microsoft AppSource — drop your email and we’ll tell you the moment it’s live.