SheetMergy vs YAMM (Yet Another Mail Merge)

YAMM (Yet Another Mail Merge) is one of the most popular Google Workspace add-ons ever built, with over 10 million downloads. It's excellent at one specific thing: sending bulk personalized emails from Gmail via Google Sheets. But if your needs go beyond email — like generating PDF invoices, certificates, or reports — YAMM simply isn't built for that. Here's where they differ.

What YAMM does well

YAMM is the easiest way to send personalized bulk emails directly from Gmail using contact data in Google Sheets. You write a draft in Gmail, add {{merge tags}}, run YAMM from your sheet, and it sends personalized emails to every row. It tracks opens, clicks, replies, and bounces. For basic email outreach it's hard to beat for simplicity.

Where YAMM falls short

YAMM is purely an email tool. Its limitations are significant if document generation is part of your workflow:

• No document generation — YAMM cannot create PDFs, Google Docs, or any file output. Email only.
• Daily sending limits — capped at 1,500 emails per day even on the paid plan, 20 per day on free
• No scheduling automation — you can schedule a batch but cannot set recurring automated runs
• No filtering logic — you can't tell YAMM to only process rows that meet certain conditions
• No grouping — no way to aggregate data across rows into a summary
• No run history — no log of what was sent or what failed
• Gmail only — exclusively tied to Gmail, no other email providers
• No DOCX support — no template upload capability at all

What SheetMergy does differently

SheetMergy is a document generation platform first, with email delivery built in — not the other way around. This distinction matters:

• Generates actual PDF or Google Docs files from your templates — not just emails
• Sends those generated documents as email attachments to recipients from your sheet
• Supports custom HTML email body, subject, CC and BCC
• Advanced filtering so only qualifying rows get documents generated
• Full run history so you know exactly what was sent and when
• Scheduled automation runs on any interval you set
• No daily sending caps tied to Gmail limits — generates and sends based on your document quota
• Works with DOCX templates uploaded from your computer, not just Google Docs

The key difference in one sentence

YAMM sends personalized emails. SheetMergy generates personalized documents and then emails them.

If your goal is "send a bulk email campaign" — use YAMM. If your goal is "generate invoices / certificates / reports and email them to recipients" — use SheetMergy.