# Migrate from Mailosaur

> The three lines that change in a test, the endpoint mapping one by one, and what is not open yet.
> https://facteur.eu/en/migrate-from-mailosaur

## Change provider without rewriting your tests

The real cost of switching testing tools is not the subscription: it is the day spent rewriting assertions that already worked. Here three lines per file change, and the shape of the test stays yours.

- Three lines per file: the import, the client, the call that waits for the message
- Nothing to export: test data regenerates
- Both providers side by side, for as long as comparing takes

## What makes a team move

- **Volume stops being counted per day** : Their plans include a volume of emails per day: a suite that runs hard on release night hits the daily ceiling even when the month is quiet. Here the volume is monthly, and overage is bought as packs valid for a year.
- **SMS lands in the same tool** : There, SMS is a module billed on top. Here, the text message arrives in the same inbox and is read with the same call as the email.
- **Per-inbox quotas, with their alerts** : A ceiling per inbox and an alert threshold: a runaway test stops on its own quota instead of consuming the whole organisation’s capacity. It is the one step of the migration the old tool did not allow.
- **The code arrives already extracted** : Our library returns the one-time code, the links and the codes as fields of the message: what your tests fished out with a regular expression is already done on reception, so the assertion gets shorter.

## Five steps, none irreversible

The first test moves in ten minutes, and it tells you whether the whole suite will move.

- **Create an account and an inbox** : The free plan is enough to validate the migration. Note the inbox identifier: it plays the role of the “server ID”.
- **Move a single test** : Install our library, replace the client and the call that waits for the message, then run that test: if it passes, your suite will pass. That is the moment of truth and it costs ten minutes.
- **Run the full suite in parallel** : Keep the old provider alongside for a week, long enough to compare pass rates. We are not asking you to cancel before you are convinced.
- **Set your quotas and alerts** : This is the step the old tool did not allow. A limit per inbox, alert thresholds, and the team’s Slack channel.
- **Take the other files at your own pace** : File by file, from the flakiest to the calmest. Nothing says finish this week: the two tools live side by side as long as you want.

## API endpoint conversion table

Where each of your current calls lands, if you call the API directly rather than through a library. The rows marked “coming” are not open yet: we would rather say so here than let you find out mid-migration.

- At Mailosaur
- At Facteur
- Note

- A Mailosaur “server” is an “inbox” here. The vocabulary changes, the semantics do not.
- Same criteria, the same ALL / ANY matching logic, with the blocking wait on top.
- Compatible response structure, enriched with otp, links, codes and extract.
- Identical binary download.
- .eml export.
- SPF, DKIM, DMARC and spam score. Neither the endpoint nor the plan that will carry it is settled.
- TOTP code generation from a shared secret.
- Enriched: breakdown per inbox, remaining credits and expiry date.

### What has no equivalent here

Rendering previews across mail clients, the visual editor and automatic rules have no equivalent here, and will not: it is not the same product. If your suite depends on them, write to us at

## Frequently asked