Shared mailboxes: support@ in Mail for the people who answer it, and in workflows for the projects given it
A mailbox several people answer. Somebody with Manage connectors adds one in Settings ▸ Connectors ▸ Shared mailboxes: signing in as the mailbox with Google, as somebody with Full Access to a Microsoft 365 shared mailbox, or with a mail server's password. The next step asks who reads it, with you already on the list, and which projects may use it, with none chosen until you pick. Its page holds who signed it in, the name it sends as, its members (people, and roles), its projects, its signature, its rules and Disconnect. Managing connectors doesn't make anybody a reader.
In Mail, for its members. It sits under your own mailboxes, headed with its organization's name. Read and starred marks and drafts are the mailbox's, so a thread a colleague is answering says Grace's draft, and a reply goes from the mailbox with its signature. Your unified folders stay your own. Create task from one of its threads offers only the projects it is given. Settings ▸ Mail lists it under Shared with you, where its menu says whether it reaches your phone: nobody, until you choose. Its rules file tasks, start runs, archive, mark read and star, as the organization, and never send.
In workflows. An on: mail trigger can hear a
shared mailbox the project is given, acting as the organization. A mail
step with from: support@acme.com drafts a message the
mailbox sends: its review shows From locked to the mailbox, and only its
members who hold Send mail from runs may approve. Anybody else
can change the draft and save it for them.
On the web, the desktop app, the iPhone, the iPad, the Mac and Android.