Dynamic Attachment Injection unique files per contact
Put a file path in Excel and use the [[Attachment]] merge tag — each contact receives their own PDF, invoice, or image with a personalized caption. Agencies send hundreds of client-specific documents in one automated run.
Everything you need to get started
Follow these steps in WhatSender Pro to activate this feature in minutes.
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Add an Attachment column in Excel with full paths e.g. C:\Invoices\client_001.pdf
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Import sheet and map the column to the Attachment variable.
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Insert [[Attachment]] in the message body and preview one row before bulk send.
Step-by-step guide
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01
Add an Attachment column
In Excel, create a column with full local paths to each file.
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02
Map the column on import
During import, link the column to the Attachment variable.
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03
Insert [[Attachment]] in message
Add the tag in your text body. Pair with [[Full Name]] in the caption.
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04
Preview one row
Confirm the correct file loads for sample contacts before bulk send.
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05
Send campaign
WhatSender attaches the matching file per row automatically.
How this helps your business
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Personalized invoices at scale
Send unique PDFs to hundreds of clients in one run — no manual forwarding.
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Fewer support tickets
Customers receive the right document the first time.
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Agency-ready workflows
Deliver client-specific creatives from a single master sheet.
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Audit trail
Delivery reports log which file path was sent to each number.
Best practices
- Use consistent folder structure — broken paths fail silently in preview.
- Keep PDFs under 5 MB for faster per-row attachment.
- Name files with client ID for easier troubleshooting.