Send SaaS trial follow-up emails with MongoDB and Gmail

Send SaaS trial follow-up emails with MongoDB and Gmail

Lifecycle & Email
n8n
Avkash Kakdiya's template reads trial start dates from MongoDB and routes each user to whichever of four emails matches their day.
Source
n8n
Tools
MongoDB, Gmail
Runs
Daily
Cost
Free template
Last updated
August 7, 2026

What it is.

A Schedule Trigger runs daily, pulls trial users from MongoDB, works out how far into the trial each one is, then a Switch node sends the matching email through Gmail. Four messages: day 3 encouragement, day 7 mid-trial, day 13 near-expiry, and a final one on the last day.

It's a small template, and the logic is a date calculation plus a Switch. Swapping MongoDB for Postgres, or for an HTTP call to your own API, is a single node change.

What you get.

  • Four trial emails on a set schedule, at day 3, day 7, day 13, and the last day.
  • A daily Schedule Trigger, so nothing depends on your product firing a webhook.
  • A batching loop, so a large user table gets processed in chunks.
  • Plain JavaScript date logic you can read and change.
HOW TO USE IT

How to set it up.

1

Point the MongoDB node at your users collection and name the field holding the trial start date.

2

Set the Gmail credential, since the template sends from whichever account you connect. Use a monitored one.

3

Edit the Code node to match your own trial length, because the day thresholds are written into it.

4

Rewrite the four email bodies in the Gmail nodes before you enable anything.

5

Set the Schedule Trigger to a time your users are awake in their own timezone.

6

Run it against a test record at each of the four day marks before you point it at live users.

Use cases

Trial sequence with no marketer

Read the start dates and let the four emails go out on their own schedule.

Nudge before the trial ends

Catch the last day with a message while the account is still open.

Run it off your own database

Trigger from the dates you already store instead of syncing to a sending tool.

Best for

A trial with no lifecycle tool

Before a dedicated messaging platform is worth the spend, four scheduled emails cover most of the value.

Products with no event tracking

It works off a date field, so you need no event tracking at all.

Testing trial messaging

Changing one of four emails and reading the conversion difference is a cheap experiment.

Open the original.

Hosted on n8n, free to open.
Open the Tool

Questions about Send SaaS trial follow-up emails with MongoDB and Gmail

Does it know what the user did in the product?
Can I change the trial length?
Is Gmail a sensible sender?

Questions about Lifecycle & Email

Should trial emails be timed or triggered?
How many emails does a trial need?
Strengths
  • Date-based, so it runs before you have product events wired anywhere.
  • Small enough to read end to end, so you know exactly what it will send.
  • The Switch node makes the day thresholds visible, so adding another email is one branch.
Limitations
  • Day thresholds live in the code, so a longer trial needs the logic edited too.
  • Gmail sending ties your deliverability to one mailbox, so a large list belongs on a proper sending service.
  • It sends on the calendar and knows nothing about what the user did in the product, so an activated user still gets the day 13 nudge.
Skip this if
  • Skip it if your sending platform already triggers off trial dates in the product.
Ideal for
  • PLG marketers
  • Founders
  • Stage: Pre-seed to Series A

Want this running without building it yourself?

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