Agencies: manage email for 50 client domains from a single account

A web agency that ships a site almost always ships an email address with it: a contact@ that has to land somewhere, a billing@, sometimes a form that sends as no-reply@. For one client, it is a detail settled in ten minutes at the registrar. For thirty, it is a patchwork: OVH redirects set by hand and never documented, two clients on per-seat Google Workspace, a third whose contact@ still lands in the owner's personal Gmail. Nobody knows who has access to what, and every client departure turns into DNS archaeology.

This guide describes a cleaner way to structure the email of a client-domain portfolio — with SMTPy, since it is our product, but the principles apply to any tool, and we also tell you honestly when a competitor is the better choice.

What an agency should demand before choosing a tool

Three criteria matter more than the feature list:

• Never delegate the client's name servers. The client's DNS stays at their registrar (OVH, Gandi, Ionos…); the email tool should only require MX, SPF, DKIM and DMARC records to copy-paste. A tool that demands taking over the name servers — as Cloudflare Email Routing does — commits the client's entire DNS, not just their email. The day the client leaves, separation is far more painful.
• Reversibility per client. A client domain must be able to leave the agency account without breaking the rest: export the addresses and messages, repoint the DNS records, done. The addresses live on the client's domain — they belong to the client, not to the agency or the tool.
• A cost that depends on neither the number of clients nor the number of mailboxes. Google Workspace or Fastmail bill per user: equipping thirty client contact@ addresses at €5-6 per mailbox is €150-180/month for addresses that receive ten messages a week. The right model for an agency is a flat account fee, not a per-address one.

Structuring the account: one domain per client, aliases per purpose

SMTPy's Business plan covers 50 domains in a single account, with unlimited addresses on each, for €29/month (€23.20/month billed annually). The structure that works:

• One domain = one client. Each domain has its own DNS records, its own verification status, its own aliases. The "My domains" view doubles as a portfolio dashboard: you see at a glance which client has a failing DMARC or a broken MX.
• Aliases per purpose, not per person. contact@, billing@, sales@, support@ — forwarded to the client's real mailbox(es), or handled directly in SMTPy's web inbox if the client has no mail service of their own.
• One catch-all per domain so nothing is lost: anything arriving at an undeclared address is collected instead of bouncing. Useful during a migration, or for clients whose usage you do not fully know yet.
• Up to 5 team members on the account: each project manager accesses the domains they run, with an audit log of actions. The account no longer belongs to one employee's personal inbox.

The Business plan's ceilings — 100,000 emails/month, 90-day message retention, 10 GB of storage — are sized for real business correspondence, not bulk sending. If a client does marketing email, that is a different job and a different tool (Brevo, Mailjet…); SMTPy handles the correspondence.

The setup, client by client

For each newly delivered site, the procedure takes four steps and a quarter of an hour:

1. Add the domain to the agency account. SMTPy generates the MX, SPF, DKIM and DMARC records to publish.
2. Publish the records in the client's DNS zone — at their registrar, without touching the name servers. If the agency already manages the zone for the site, it is the same gesture as adding an A record.
3. Wait for automatic verification. SMTPy checks propagation and marks the domain "verified" without intervention; DMARC monitoring stays active afterwards, which avoids discovering a broken SPF three months later because a contractor edited the zone.
4. Create the aliases (contact@, billing@…) and their destination: the client's existing mailbox, or inbox mode to handle messages inside SMTPy.

The domain then lives its life in the portfolio. At the end of the contract, exporting and repointing the MX records hands the domain back to the client in the state it should always be in: documented and autonomous.

What it costs, honestly compared

At €29/month for 50 domains, the per-client cost of a full portfolio is about €0.60/month — rebillable, or folded into the maintenance retainer. The honest comparison:

• Free registrar redirects (OVH, Gandi) remain unbeatable on price for an isolated client who just wants forwarding. What they lack: the centralized multi-client view, replying from the address, retention, DMARC monitoring.
• ImprovMX goes up to 100 domains on its Pro plan — double our ceiling. Beyond 50 client domains, it is the one to look at. It is pure forwarding: no web inbox, no message retention.
• Forward Email covers an unlimited number of domains, free for pure forwarding. If the agency only wants to forward and can configure IMAP, it is the best coverage-to-price ratio on the market.
• Google Workspace remains the right choice when the client wants a full mail service in their own name, with calendar and video calls — but that is then the client's own per-seat subscription, not a service the agency pools.

SMTPy earns its place when the agency wants all three at once: portfolio centralization, an interface to read and reply from client addresses, and data hosted in France by a French company — an argument that matters when the end client is a public body or answers to tenders.

Conclusion

Client email management does not have to be the agency's messy drawer. One account, one domain per client, aliases per purpose, DNS that stays at the client's registrar: the structure is simple and it survives departures — of clients and of agency staff alike.

The Business plan is €29/month, with a 14-day trial, no commitment. Create your agency's account →

Going further: Email aliases: the complete guide · Understanding catch-all · Understanding DMARC