How do I send a PDF attachment with a Gmail mail merge?

Updated October 29, 2026

Short answer

If everyone should get the same PDF, attach it to the campaign once and the tool adds it to each personal email. In Mergeline Pro, open “Copies and attachments”, add the PDF, and it goes with the first email to every person. Keep files under 15 MB in total so Gmail accepts every email. For a different PDF per person, use a link column instead.

Same PDF for everyone in Mergeline

Build your list and write your email as usual.
Open the “Copies and attachments” section and add the PDF. You can add more than one file.
Check the preview: the file name shows under the first email.
Send a test to yourself and open the attachment from your inbox.
Press send. Each person gets their own email with the PDF attached.

Attachments are part of Pro ($12 a month or $99 a year). They are added to the first email only, so your follow-ups stay light and land in the same thread.

When a link beats an attachment

Big files make every email heavy, and some company mail servers strip or hold attachments from people they do not know. For a cold email or a large file, a share link to Google Drive is often the better choice: the email stays small and you can update the file later.

Write a short line that says what the file is, like “Here is the 2-page price list (PDF)”, so the link does not look like a surprise.

A different PDF for each person

Invoices, certificates and tickets need one file per person. No normal attachment field does that. Use a column with each person’s link, or create personal drafts and attach files by hand. The steps are in different attachment for each recipient.

Check the file before you hit send

Open the PDF you attached, not the one on your desktop, to confirm it is the final version.
Give it a clear name, like “Price list 2026.pdf”, since the file name shows in every inbox.
Keep it small. Compress scanned pages before attaching.

Read the full guide: Mail merge with attachments

Sources

r/Outlook: mail merge with unique attachments

Facts checked October 29, 2026. Google and other vendors change their limits and prices, so check the source before you rely on a number.

Mergeline does this from your own Gmail. Free for 60 emails a day with merge tags and no branding. Pro is $12 a month or $99 a year for follow-ups, scheduling and attachments.

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