Mailbox capabilities and limits

Reviewed on March 20, 2026

This page provides information about the capabilities and limits of Scaleway Mailbox.

Mailbox quotas

• Mailbox storage: up to 20 GB per mailbox (for emails, attachments, and mailbox folders).
• Number of Mailboxes: 20 Mailbox email accounts per project (during Beta phase). If you need to create more mailboxes, contact Scaleway Support.
• Number of aliases: 5 aliases per Mailbox email account (during Beta phase). If you need to create more aliases, contact Scaleway Support.

Message limits

• message (the maximum number of messages that can be submitted per SMTP session): 10
• size (the maximum size of a message): 104857600 bytes (100 MiB)
• received-headers (the maximum number of received headers that a message can contain): 50

Supported ESMTP extensions

Mailbox SMTP relay supports the following ESMTP extensions:

• 8BITMIME
• BINARYMIME
• CHUNKING
• ENHANCEDSTATUSCODES
• NO-SOLICITING
• PIPELINING
• REQUIRETLS
• SIZE 104857600
• SMTPUTF8
• STARTTLS