Run every client's outreach from one tool — without your bill scaling by headcount.
Hosted cold-email platforms charge per seat, which punishes agencies for the exact thing that makes them work: adding account managers as you add clients. SubsiMail runs on your own server and charges per connected inbox. Add ten people to the team tomorrow and the bill doesn't move.
One instance. Every client. Nobody sees what they shouldn't.
Give each account manager their own login and scope their view to just the clients they run — without paying a per-seat fee for every hire, and without exporting anyone's list to a shared platform where another agency's bad list can tank your sender reputation.
Unlimited team members, always
Every plan is priced by connected inbox, not by seat. Onboard your whole team — account managers, SDRs, a client's own staff — without the invoice changing.
Per-client data separation
Give each client a workspace with its own contacts, campaigns, mailboxes, templates and plan. People only see — and can only switch to — the workspaces you give them, with a role per workspace. Enforced everywhere, UI and API.
Each client sends from their own inbox
Connect each client's own Gmail, Outlook, or SMTP account. There's no shared sending pool, so one client's cold list going sideways never touches another client's deliverability.
An audit trail for every account
Every change records who, when, and from where. Useful the first time a client asks "who edited this sequence" — and it's on every plan, not an add-on.
Two ways to run it
Shared instance
One SubsiMail deployment for the whole agency. Use per-resource sharing to scope each client's campaigns and contacts to the account managers running them.
One instance per client
Prefer full isolation? Each deployment is one Docker container on a $5/month VPS — cheap enough to run a separate instance per client if that's a better fit for how you bill or report.
Hybrid
Keep smaller retainer clients on the shared instance, and spin up a dedicated one only for clients who need full isolation or run higher volume.
Onboarding a new client and don't want to do it by hand?
One-time $50 and we'll deploy a SubsiMail instance, connect the first inbox, and hand it over running — per client, if that's how you want to run it.
What client-facing teams actually use
Prebuilt roles
Super Admin, Admin, Manager, and View Only — hand a client read-only access to their own results without giving them the keys.
Webhooks for client reporting
Fire reply/open/click events into Slack, a client dashboard, or your own reporting stack as they happen.
Full REST API
Pull performance data into whatever you already use to report to clients, or drive campaign creation from your own tooling.
Per-campaign sending windows
Run a US client's campaign on their business hours and an EU client's on theirs, from the same instance.
Suppression lists
Global unsubscribe and do-not-contact handling, enforced automatically across every client's campaigns.
Contact lists & custom fields
Keep each client's list segmented and track whatever fields matter — deal stage, source, region.
FAQ
Does the price go up as we add team members?
No. Every plan includes unlimited team members — you pay for connected inboxes, not seats. Add your whole account team without the bill changing.
Can one account manager be blocked from seeing another client's list?
Yes. Give each client a workspace and give people access to just the workspaces they work on, with a role per workspace — they only see, and can only switch to, those. Inside a workspace you can still scope a campaign, list or template to specific people. All of it is enforced in the UI and the API, not just hidden in a menu.
Should we run one install for the whole agency, or one per client?
One. Give each client a workspace: its own contacts, campaigns, mailboxes, templates and plan, completely apart from the others, behind the same login and URL. Switch between clients from the menu. If a client ever asks where their data lives, it is on your server, in a workspace only the people you chose can open.
What does it cost to add clients?
Each workspace has its own plan, priced by connected inboxes like any other. Two workspaces are free; the second paid workspace is 20% off and every one after that 10% off, monthly or yearly.
Can each client have its own tracking domain?
Yes, set per workspace on your subsimail.com account — and you can keep your login private on a VPN while the tracking port stays public. See Tracking domain & VPN.
What if a client wants to take their instance with them when they leave?
It's already theirs if you deployed it on their own server. If it's on agency infrastructure, export their contacts to CSV and hand over the database file — nothing is locked to us.