Mail bootstrapper

Auto-detected when @adonisjs/mail is installed. Lets each tenant ship outbound mail under their own brand without forking your mailers.

What it does

For the duration of the tenant context, mail.send(...) resolves the SMTP credentials and the from address from the tenant's branding record (or any row source you configure). Outside the tenant context, mail uses your default config.

Configuration

// config/multitenancy.ts
export default defineConfig({
  mail: {
    enabled: true,
    resolver: async (tenant) => {
      // Anything you want — this is just a function.
      return {
        from: tenant.brandingFrom ?? `noreply@${tenant.customDomain}`,
        // Per-tenant SMTP override, or null to use the default mailer.
        smtp: tenant.smtpHost
          ? {
              host: tenant.smtpHost,
              port: tenant.smtpPort,
              secure: tenant.smtpSecure,
              auth: {
                user: tenant.smtpUser,
                pass: tenant.smtpPasswordPlaintext, // see Branding service for at-rest encryption
              },
            }
          : null,
      }
    },
  },
})

At-rest encryption

When tenants store SMTP passwords, they belong in the tenant_brandings table with the encrypted column treatment from utils/crypto.ts. The BrandingService handles encrypt-on-write / decrypt-on-read. Avoid plain text columns.

Reply-to and tracking

Same idea; read whatever you need from the tenant row and return it from the resolver. The bootstrapper trusts your resolver completely; it does no tenant-specific transformation beyond what you tell it.

Common pitfall

Setting from per tenant changes the DKIM signing domain that your provider uses. If your tenants bring their own domains, ensure each domain has the right DKIM record published; otherwise your emails land in spam.