I built Notavia v1, a notification API for multi-tenant .NET SaaS — per-tenant sending domains, in-app inbox, SMS, chat

Disclosure: I build Notavia.

The hard part of email in multi-tenant SaaS was never calling SES or SendGrid. It was everything around that.

Customer A wants mail from their domain, not yours. Then you need SPF/DKIM/DMARC, DNS verification, tenant/domain mapping, suppressions, retries, branding, logs. Then later someone asks for in-app, SMS, Slack, etc.

I got tired of rebuilding that layer, so I built Notavia.

What it does:

• Per-tenant sending domains
• SPF/DKIM/DMARC setup and verification
• Per-tenant suppressions and branding
• Email, in-app, SMS and chat behind one API
• Idempotency, signed webhooks and delivery logs
• White-label / OEM
• .NET SDK and a real Blazor inbox component

Example:

csharp await notify.Notifications.SendAsync(new SendNotificationRequest( Channel: "email", Recipient: new Recipient("ada@example.com")) { TemplateKey = "welcome", TemplateData = new Dictionary<string, object?> { ["name"] = "Ada" } });

Current state:

• It’s new and mostly built by me
• Free is 1,000 emails/month with your own provider
• Managed sending, inbox, SMS and chat are on paid plans
• .NET, TypeScript, Python, Go and PHP SDKs are out
• Java and push are still coming

Product: https://saas-infrastructure.com/products/notify?utm_source=reddit&utm_medium=launch&utm_campaign=launch-2026-08

Blazor inbox: https://saas-infrastructure.com/blog/add-in-app-inbox-blazor

If you’ve done per-customer sending domains in production, I’d like to hear what caused you the most pain.