Vectis Mail for SaaS founders.
Flat-priced email infrastructure that scales with you, not against you.
Vectis Mail is what you get when transactional sending, inbound webhooks, mailbox hosting, and multi-domain management ship as one self-hosted product instead of three separate SaaS bills. Pro is $39 USD per tenant per month: unlimited domains, unlimited volume, unlimited installs operated by your organisation. The math compounds in your favour as you grow.
The SaaS-specific case
Five things SaaS founders consistently say about transactional email infrastructure. Each maps to a specific Vectis Mail capability.
1. Per-email pricing kills unit economics
SendGrid, Postmark, SES, and Resend all price per email past a base bucket. As your sending volume grows linearly with customer count, your email cost grows linearly with your cost-of-revenue. Vectis Mail charges per tenant, not per email. SendGrid math · Postmark math.
2. You shouldn't pay for mailboxes twice
SendGrid + Google Workspace for support@ is two vendors, two bills, two integration surfaces. Vectis Mail hosts mailboxes (IMAP/POP3 + Roundcube webmail) and runs the transactional API on the same instance. One product, one cost line.
3. Multi-domain SaaS needs per-domain isolation
Every domain gets its own DKIM keys, analytics, and spam controls, isolated per domain. One install hosts many customer domains; one Pro subscription covers unlimited installs you operate, so you can run a dedicated install per customer when a client needs hard isolation. (Single-install isolation between mutually-distrustful tenants, and per-client white-label, are on the Phase 4 roadmap.)
4. Data sovereignty closes deals
Selling into healthcare, government, financial services, or EU public sector? Buyers increasingly require email content + metadata to stay in their jurisdiction. Vectis Mail runs on your VPS, so you choose where the data lives and who can touch it. With a managed provider the content sits on their infrastructure — even a regional option runs on their servers, under their control.
5. Reply-handling is part of the product
Real SaaS flows have inbound: ticket-by-email, reply-to-thread, support-mailbox automation. Vectis Mail ships HMAC-signed inbound webhooks with exponential-backoff retry, so receiving + parsing inbound mail is one HTTP POST your app handles like any other event.
6. Atomic updates don't break Friday afternoon
The orchestrator runs Snapshot → Migrate → Pull → Deploy → Health-check → Complete with automatic rollback on failure. No "re-run the setup script and hope" model. Worth caring about when your email is on the critical path for password resets, payment receipts, and ticket notifications.
The flat-pricing math at SaaS scale
What you'd pay sending the same volume through different providers.
| Monthly emails | Vectis Mail Pro + ~$20 VPS | SendGrid Email API | Postmark Pro / Platform |
|---|---|---|---|
| 10,000 | $39/mo flat | $19.95 | $15–18 |
| 100,000 | $39/mo flat | ~$89.95 | ~$134 |
| 500,000 | $39/mo flat | ~$120 | ~$654 |
| 1,000,000 | $39/mo flat | ~$150–250 | ~$1,200 |
| 5,000,000 | $39/mo (may need a larger VPS at this scale) | ~$2,000+ | ~$6,000 |
Vectis Mail is the flat $39/mo Pro tier; add a ~$20/mo VPS to host it for an all-in of about $59/mo at any volume. Provider pricing per Twilio's published Email API pricing + Postmark's published pricing, retrieved 2026-05-13.
The exact crossover depends on which provider you're comparing against, but the pattern is consistent: past a few hundred thousand emails a month, the flat cost is a fraction of per-email pricing, and by a million or more a month the annual difference runs well into five figures — while your Vectis Mail bill stays flat.
What you build on Vectis Mail
Concrete SaaS patterns that Vectis Mail handles cleanly.
Multi-domain transactional email
Each of your customers gets their own sending domain. Vectis Mail handles DKIM key generation, DNS record publishing (or guidance for customers managing their own DNS), per-domain rate limiting, and per-domain deliverability analytics. Your code calls one API; routing to the right domain is config.
Mail for client domains (agency / reseller)
Running mail for client domains? Host many client domains on one install, or run a separate install per client (per geo, per customer tier, or per major client) — all under a single Pro subscription. The "unlimited Vectis installs per organisation" policy is built for this. Pro's Custom Branding sets the admin dashboard's name, colour, and logo today; per-client webmail/admin white-label branding is on the Phase 4 roadmap.Compare to the per-instance pricing on managed providers.
Reply-to-resolve support flow
User emails support@yourdomain. Vectis Mail receives, parses, and POSTs the full message body + attachments to your app's webhook endpoint (HMAC-signed, with exponential-backoff retry on failure). Your app creates a ticket, runs sentiment analysis, replies via the sending API, all without a second mail vendor in the loop.
Compliance-grade audit + retention
Every send + receive + admin operation lands in the audit log table (your Postgres). Retention is your call: keep 30 days, keep 7 years, keep forever. Useful for SOC 2 readiness on your side, and for the "we have your data in our region" answer to enterprise procurement.
Per-domain analytics for client transparency
Pro ships a per-domain analytics dashboard: delivery rates, bounce rates, IP warmup progress, RBL status. Surface those metrics to your clients in your own admin UI via the analytics API, and they see "your delivery rate this week" without ever seeing the underlying provider.
Where Vectis Mail isn't the right fit (yet)
What we don't yet do. If any of these is critical, factor it in.
Message Streams
Postmark's built-in transactional/broadcast reputation separation has no exact Vectis Mail equivalent. The workaround (separate sending domains) works but isn't a built-in feature in Vectis Mail. If multi-stream reputation is load-bearing for your business, factor that in. Detail on the Postmark comparison →
Marketing campaigns + broadcasts
Vectis Mail is transactional + receive. It's not Mailchimp. If you need list management, A/B testing of broadcast email, or sophisticated campaign analytics, you'll still want a marketing platform alongside.
Pre-warmed IP from day one
Self-hosting puts you on your own IP, which means 2–4 weeks of gradual warmup before deliverability matches a pre-warmed managed pool. If you're shipping password resets next week and can't afford the warmup, start on Postmark/SendGrid, migrate when your reputation has built.
Compliance reports off-the-shelf
Managed providers ship SOC 2 / GDPR / HIPAA reports ready for procurement. Self-hosted means you operate the controls and produce the evidence. Worth factoring into your timeline if you have enterprise procurement on the near horizon.
Frequently asked questions
Will my transactional email cost scale linearly with my SaaS growth?
Not on Vectis Mail. Pro is $39 USD per tenant per month for unlimited domains, unlimited mailboxes, and unlimited email volume. Add a ~$20/month VPS and your fully-loaded cost is $59/month whether you send 10,000 or 10 million emails. The same subscription covers unlimited installs operated by your organisation , useful for running separate instances per geo or per customer segment. Compare: SendGrid at ~$90–250+/mo at 1M emails, Postmark at ~$1,200/mo at the same volume.
How does Vectis Mail handle multi-tenancy for a SaaS with many customer domains?
One install hosts many customer domains, and each domain is isolated at the domain level — its own DKIM keys, analytics, and spam controls. When a client needs hard isolation, run a dedicated install per client: one Pro subscription covers unlimited installs you operate, so there is no per-install fee. Single-install isolation between mutually-distrustful tenants, and per-client white-label branding, are on the Phase 4 roadmap. Architecture detail at /architecture/overview.
Can I host mailboxes and run a transactional API on the same product?
Yes, that's a core design decision. The same Vectis Mail instance hosts user mailboxes (IMAP/POP3 + the Roundcube webmail) and exposes 40+ REST API endpoints for transactional sending, inbound webhooks, mailbox CRUD, analytics, and admin operations. You don't need to pay for SendGrid alongside a Google Workspace.
What about data sovereignty for selling to regulated buyers?
Vectis Mail runs on your VPS. Email content, metadata, and analytics live in your Postgres. You choose where that data resides (EU VPS, sovereign cloud, on-prem, whatever fits your jurisdiction) and who has access. For SaaS selling into healthcare, government, financial services, or EU public sector, that's often the deal-maker. Managed providers host customer email content on their infrastructure. Some offer a regional or EU-residency option, but the servers and access stay under their control, not yours.
How do I separate transactional reputation from marketing/broadcast?
Postmark's Message Streams is an architectural feature Vectis Mail doesn't replicate cleanly. The pattern that works on Vectis Mail is to run separate sending domains (e.g. notifications.yourapp.com for transactional,mail.yourapp.com for broadcast) with separate DKIM keys, so reputation builds independently. For very high-volume SaaS, you can also run two Vectis Mail installs under one Pro subscription. See thedeliverability guide.
What's the migration path from SendGrid or Postmark?
Mechanical for the API code: swap the SDK call for an HTTP POST, re-map webhook field names, re-create templates locally. The gating factor is IP warmup: 2–4 weeks of gradual volume ramp before your new IP has reputation equivalent to a pre-warmed shared pool. Run dual-send during the warmup window — most teams find a clean cutover takes around 5 weeks total. See theSendGrid orPostmark alternative pages for the full sequence.
Try Vectis Mail for your SaaS
Self-hosted transactional sending + mailbox hosting + multi-domain management. Flat $0–59/month all-in.
Free Starter tier · No credit card required · Source-available