The settings
Point your app at mx.rovela.dev on port 465 with SSL/TLS. Sign in with the mailbox’s full address and a credential you create for that device in the dashboard, the same one the device uses for IMAP.
Standard SMTP, with the safeguards on
Any SMTP client
Outlook, Apple Mail, Thunderbird, phone mail apps, and software such as Nodemailer or PHPMailer configured with a mailbox credential.
TLS on port 465
Implicit TLS is required from the first byte, at TLS 1.2 or later. No password ever crosses an unencrypted connection.
Sends only as itself
A mailbox can send only as its own address. A leaked credential cannot be used to impersonate anyone else on your domain.
Per-domain DKIM
Every message sent over SMTP is signed with your domain’s DKIM key, with SPF and DMARC aligned.
Sensible limits
Up to 50 recipients per message and 30 messages a minute from one client address, which covers a person or a small app and stops a compromised client from flooding your domain.
A credential per device
Each device or app gets its own credential, used for both IMAP and SMTP. Revoke one and only that device is cut off.