Mailboxes and mail clients

A mailbox is a real address on one of your domains, with its own password for IMAP and SMTP. The address is the login: hello@yourdomain.com. Mailboxes are unlimited on every plan and are managed from Mailboxes.

Creating a mailbox

1. Open Mailboxes → New mailbox.
2. Choose the domain and the local part (hello). The local part must be unique on that domain.
3. Optionally give it a display name, such as Support or your own name. It labels the mailbox in the dashboard and is the sender name recipients see on everything sent from it, whether from the dashboard or from a mail client that sets none of its own.
4. Leave Belongs to on The whole team for a shared mailbox, or choose a teammate to make it personal to them. The choice appears on plans that include personal mailboxes.

Creating, changing and deleting mailboxes is for the owner and admins; see roles.

The password is generated when the mailbox is created and is shown on the mailbox page, where it can be revealed and copied at any time. It is only for IMAP and SMTP; it is not your FounderMail sign-in.

A mailbox on a domain that has not yet verified receives nothing until the domain does. There is no catch-all: mail to an address that does not exist on your domain is refused at delivery, so the sender receives a bounce rather than the message disappearing.

Personal mailboxes

A mailbox is either shared or personal. A shared mailbox, such as hello@ or support@, is read by everyone on the team. A personal mailbox, such as maria@, belongs to one person: only they see its mail in the inbox, in the conversation list, in search and in the message counts beside a contact. The rest of the team, the owner and admins included, sees on the Mailboxes page that the mailbox exists, with a Personal badge and whose it is, and nothing of what is in it.

• Separate threads. Mail that arrives in a personal mailbox never joins a shared conversation. A customer who writes to hello@ and to maria@ in one message starts two conversations: a shared one the team sees, and one only Maria sees.
• The password. Only the mailbox's own person sees its password on the mailbox page; everyone else sees a note saying who can. If an admin or the owner resets it, the new password is shown to nobody else and emailed to nobody: the person is told by email that it was reset, and reads the new one on their mailbox page. They can reset it themselves from the same page.
• Handing it over. An admin or the owner changes whose a mailbox is from the mailbox page's actions menu (Owner): to another teammate, or back to the whole team. The people involved are told by email. The previous person stops seeing its mail at once; a mailbox made shared shows its mail to the whole team.
• Everything else is the same. A personal mailbox has the same IMAP and SMTP settings, folders and aliases as a shared one, counts toward the same allowances and storage pool, and anyone who has its password can use it in a mail client. The REST API and the MCP server read every mailbox in the workspace, personal ones included: an API key belongs to the workspace, not to a person.

Personal mailboxes start on Plus. Each person on the team may hold one on Plus, three on Pro and five on Scale; Free has none. Making another one personal past that number is refused with the plan that would allow it; mailboxes that are already personal stay so after a downgrade.

Aliases

An alias is a second address that delivers into a mailbox you already have: info@yourdomain.com arriving in hello@yourdomain.com. It receives only. It has no password, no login, no folders and no storage of its own; mail to it lands in the mailbox exactly as mail to the mailbox does, counts once against the received allowance, and replies leave from the mailbox's own address. An alias can sit on any of your domains and point at a mailbox on that domain or on another of yours. An address is a mailbox or an alias, never both, and there is still no catch-all.

To add one, open the mailbox page and find the Aliases card: type the local part (info), choose the domain and press Add alias. Mail to the new address is accepted within a minute. Removing an alias means mail to that address is refused from then on; nothing already delivered is touched.

Aliases start on Plus: three there, unlimited on Pro and Scale, none on Free. Aliases you already have keep delivering if you move down a plan; you are only stopped from adding another. An alias is for your own addresses. To send mail on to an address outside your account, use a forwarder. The REST API and the MCP server do not manage aliases yet.

Connecting a mail client

Any client that speaks IMAP works. The settings are the same for every mailbox:

Most clients find these settings on their own from the address. The mailbox page has a Send a sample email button that delivers a message into the mailbox, so you can confirm the client sees it.

A message submitted over SMTP goes through the same outbound rules as the dashboard: the domain must be verified for sending, the recipient must be allowed under the domain's outbound access, and the month's send allowance must have room. A refused message is reported to the client as an SMTP error with the reason, and nothing is silently dropped. See Sending and outbound access.

Folders

Every mailbox has Inbox, Sent, Drafts, Junk, Trash and Archive. They are advertised to IMAP clients with their roles (RFC 6154 SPECIAL-USE), so a client maps its Sent and Trash buttons correctly on first connection instead of guessing from names. Clients may create, rename and delete their own folders; those folders are IMAP-only and do not appear in the dashboard's views.

The IMAP server supports IDLE (new mail is pushed to the client), MOVE, UIDPLUS, QUOTA, NAMESPACE and LIST-EXTENDED. Flags set in a client (read, flagged, deleted) are the same flags the dashboard shows, and the other way round: starring a thread in the dashboard flags it in your client.

Storage and quota

Storage is pooled across the workspace: 1 GB on Free, 15 GB on Plus, 50 GB on Pro, 250 GB on Scale. The mailbox page and Analytics show what each mailbox uses, summed from its messages and attachments. Mail keeps arriving when the pool is full; the owner is warned and asked to upgrade. IMAP clients can read the allowance through the QUOTA extension, and an upload from a client over the allowance is refused with an over-quota response. Free includes twelve months of mail and Plus, Pro and Scale keep everything; nothing is deleted for age.

Enabling, disabling and deleting

• Disable stops the mailbox receiving and stops its IMAP and SMTP login. Existing mail is kept and the mailbox can be enabled again.
• Delete removes the mailbox and all its messages permanently. Copy anything you need out over IMAP first.

The mailbox page

Each mailbox's page shows its address and status, whom it belongs to, the mail client settings with a copy button for each value, the password (for a personal mailbox, only to its person), usage (messages and storage), the capture switch, its aliases, and the sample-email button. Clicking a mailbox in the inbox's rail filters the inbox to that mailbox; the eye icon beside each one shows which mailbox is currently selected.