Multi Tenancy Email Routing

Multi-tenancy: email routing & mailboxes

Part of the Multi-tenancy section. Planned / in design.

When a multi-tenant install receives an email, it has to decide which company the ticket belongs to. This page explains how — and how it bends to very different ways of working.

Domains belong to the company, not the mailbox

Each company registers the email domains it owns — acme.com, and maybe also acme.co.uk. A company can own several domains. Mailboxes do not own domains; companies do.

Every mailbox is one of two types

This is the heart of it — and a perfect example of flexibility living in the entity rather than a global switch. Each mailbox is set up as one of:

1. Pinned mailbox — "this inbox belongs to one company"

• You assign the mailbox to a specific company (and optionally a department).
• The mailbox decides the company. The sender's address is irrelevant — everything arriving here belongs to that company.
• It's also the reply identity: replies to its tickets go back out from this mailbox, so the client sees their own helpdesk end to end.
• Great for: a single company's own helpdesk, or an MSP that dedicates a separate inbox to each client.

2. Shared intake mailbox — "one inbox, sorted by sender"

• The mailbox is not pinned to a company.
• An arriving email is filed by matching the sender's domain against the companies' registered domains (someone@acme.com → Acme).
• An unmatched sender drops into the triage queue (below) — never lost.
• Great for: an MSP running a single professional address like support@themsp.com for all clients. This is the recommended default for MSPs.

A ticket remembers which mailbox it came in on, and replies always go back out from that same mailbox — the mailbox is the company's email identity, both inbound and outbound.

A company can use both at once

A company isn't locked into "one mode". Acme might receive most mail via the shared support@themsp.com and have a dedicated helpdesk-acme@themsp.com for VIPs. Both feed Acme. That's exactly why the pinned-vs-shared choice lives on the mailbox, not on the company.

How an incoming email finds its company (in order)

1. Is it a reply to an existing ticket? → it joins that ticket and inherits its company. (A thread stays glued to one company even if someone replies from a different address.)
2. Did it arrive in a pinned mailbox? → that mailbox's company. Sender ignored.
3. It arrived in a shared intake → match the sender's domain to a company. No match → triage.

In a single-company install only step 2 ever fires, which is why none of this is visible until you add a second company.

The triage queue (the safety net)

When a shared-intake email matches no company domain, it lands in a Triage / Unassigned queue rather than vanishing. From there an analyst can, in one click:

• Create a new company from this domain — and the queued email (plus any others from that domain) is filed under it, with all future mail auto-routing from then on.
• Assign it to an existing company — e.g. a client that just started using a new domain.

Free-email senders

Addresses like gmail.com or outlook.com also land in triage — but you should never map a free-email domain to a company (two different clients will both have users on Gmail). Those tickets are assigned by hand, one at a time. See Pitfalls.