Transactional Email capabilities and limits

Reviewed on October 29, 2025

Scaleway's Transactional Email service allows users to send automated emails triggered by specific actions like account notifications, password resets, and order confirmations. This service is optimized for high-volume email sending, ensuring fast and reliable delivery of critical messages to end users.

The service is built on scalable infrastructure capable of handling substantial email volumes. However, sending capacities are evaluated on a case-by-case basis, depending on factors such as:

Usage patterns
Sender reputation
Adherence to best practices

New users may face stricter initial limits, while well-known customers can benefit from higher limits, potentially sending up to millions of emails. These quotas are subject to validation by the Scaleway Support team.

Important

Customers must adhere to industry standards and our General Terms of Services (PDF), including compliance with Scaleway's anti-spam policy (PDF). Failure to comply may result in temporary or permanent restrictions to the service.

Transactional Email service quotas

Quota	Default Quota	Maximum Quota	Upgradable
Maximum number of emails per month	10,000	Unlimited	Yes
Maximum number of attachments per email	10	Custom defined	Yes
Maximum number of recipients per email	10	Custom defined	Yes
Maximum email size (API)	2 MB*	2 MB*	No
Maximum email size (SMTP)	50 MB*	Custom defined	Yes

*Including the email and all attachments in the email.

Note

Quotas can be increased on a case-by-case basis. If you have validated your payment method and identity and want to increase your limits beyond the values shown, contact our Support team.

As of December 1st, 2023, the Transactional Email service no longer applies an hourly quota for email sending.

For more information on pricing, visit the Transactional Email pricing page.

Types of attachments available

The attachments available are the following:

File type	MIME type
CRL	`application/x-pkcs7-crl`
CSV (comma-separated values)	`text/csv`
DOC	`application/msword`
DOCX	`application/vnd.openxmlformats-officedocument.wordprocessingml.document`
DWF	`application/dwf`, `application/x-dwf`, `model/vnd.dwf`
DWG	`application/acad`, `application/autocad_dwg`, `application/x-dwg`, `image/vnd.dwg`
DWT	`application/acad-template`, `application/vnd.dwt`, `application/x-dwt`
DXF	`application/autocad_dxf`, `application/dxf`, `application/x-dxf`, `image/vnd.dxf`
GIF	`image/gif`
HTML	`text/html`
iCalendar	`text/calendar`
ICS	`application/ics`
JPEG image	`image/jpeg`, `image/jpg`
MP3	`audio/mpeg`
ODS	`application/vnd.oasis.opendocument.spreadsheet`
P7B, SPC	`application/x-pkcs7-certificates`
P7C, P7M	`application/pkcs7-mime`, `application/x-pkcs7-mime`
P10	`application/pkcs10`
P12, PFX	`application/x-pkcs12`
P7R	`application/x-pkcs7-certreqresp`
P7S	`application/pkcs7-signature`, `application/x-pkcs7-signature`
PDF	`application/pdf`
PNG	`image/png`
SVG	`image/svg+xml`
Text	`text/plain`
WAV	`audio/wav`
XLS	`application/vnd.ms-excel`
XLTS	`application/vnd.openxmlformats-officedocument.spreadsheetml.template`
XML	`application/xml`, `text/xml`
XSLX	`application/vnd.openxmlformats-officedocument.spreadsheetml.sheet`
ZIP**	`application/zip`

** - Available only with the Scale plan.

Important

Keep in mind that when sending an email with Transactional Email, each recipient counts as a separate email. Example: If you send an email to one recipient and you add three recipients as CC, you will be billed for 4 emails.
Transactional Email is only available in the fr-par region.
The recursive SPF include directive is not supported.
The subject, body and HTML of your emails must have at least 10 characters.

Supported ESMTP extensions

Transactional Email's SMTP relay supports the following ESMTP extensions:

PIPELINING
8BITMIME
ENHANCEDSTATUSCODES
CHUNKING
STARTTLS
SIZE

Still need help?

Create a support ticket