If your company has an address several people handle —sales@, support@— this is how it works inside Duobox and why we built it this way.
A shared inbox is an address —sales@, support@— that several people open, each from their own webmail and with their own password.
How it works inside
Mail lives on a mail server (Stalwart), where every address is an account. There were two ways to share: one account per person with the inbox delegated inside, or the same account opened by several people.
We chose the second. In our database, each person has an access to that account; the webmail signs in with that access and the server sees one account. No copies to sync and no “send as”.
You notice it when you use it: read state, folders and sent mail belong to the inbox, not to each person. If someone opens a message, it's read for everyone else too; if someone replies, the reply is in Sent for all. That's what you want from support@: knowing what's already been handled.
Inviting is asking
Whoever administers invites someone from the company, and the access is born when that person accepts. Until then they see nothing. Sharing an inbox is handing someone other people's mail, and that doesn't happen without a yes.
- An invitation not yet accepted doesn't count toward anyone's inbox limit.
- Accepting does count for the person who accepted, but it doesn't create an address or get billed as one more person.
- You can't remove the person who signs in with that address, or leave the inbox with no one.
Personal or shared, from the start
You choose when you create the address: Personal or Shared. Only a shared one gets shared; the address you sign in to your webmail with stays yours. In the hub, Addresses shows them in two groups.
We used to infer it from how many accesses an inbox had, and that didn't work: a freshly created one has a single access until someone accepts. Now it's a fact of the inbox, saved when it's created.
To create one, open your domain's Addresses in the hub, click New address and choose Shared. More changes like this one, in the changelog.