Attachments and copies · Escouade Mail documentation

An attachment is added to a draft, through an upload link the human opens in their browser. It leaves with the message, once a human approves it. Attachments and copies only go into a conversation: the correspondent has already written in the thread. A first message leaves with no attachment, to its single recipient.

What is allowed

	In a conversation	To an address of the space	First message, follow-up with no reply
Attachment	Yes.	Yes: its human, one of its inboxes.	No: `attachments_not_allowed`.
Copy (`cc`)	Yes, to someone who has written in the thread themselves, or to an address of the space.		No: `cc_not_allowed`.

A conversation: the correspondent has written in the thread themselves (a reply, or a first e-mail received). An automatic reply does not count, nor does a third party’s e-mail attached to the thread.
Who a copy can go to: an address that has written in the thread itself. Having been a recipient of a received message is not enough: an e-mail’s Cc header can be written freely.
From an inbox on the shared domain, a copy only goes to an address of the space.
A blocked address cannot be copied in: recipient_suppressed.

Bound	Value
Size of a message’s attachments	10 MB, all attachments together
Attachments per message	10
Copies per message	5
Attachments kept per space	500 MB of attachments sent, 200 MB of attachments received
An attachment’s content	kept for 90 days
Upload link	1 hour, 30 MB received at most (removed attachments included)
Upload links per space	60 per 24 hours
Uploads	One at a time per draft; 12 per minute per address
Download link	15 minutes

A file that runs on a double click (.exe, .bat, .js, .msi, .scr…) cannot be attached, nor can a page (.html, .svg): attachment_refused.

Attaching a file

The agent writes the reply as a draft: reply_to_thread with requires_approval = true.
It asks for the upload link: attach_files with the draft’s message_id, and gives it to its human.
The human opens the link in their browser and picks the files. The page shows the draft and its attachments; it lets them remove some.
The human approves the draft from their assistant: approve_message. The message leaves with its attachments.

The draft changes version with every attachment added or removed. An approval given with the old revision is refused (draft_changed): whoever approves sees the attachments that leave.
An agent that holds the file uploads it itself: a POST request to the link, as multipart/form-data, with one file field per file. With the Accept: application/json header, the response is in JSON.
The link allows nothing else: neither reading the message’s text, nor approving it, nor touching another draft. It stops working as soon as the message is approved or cancelled.
A cancelled draft does not keep its attachments. Their names remain in the message’s log.

Text

curl -H "Accept: application/json" -F "[email protected]" "https://api.subagent.fr/f/sfl_…"

Reading an attachment received

An e-mail received keeps its attachments. get_thread and get_message list them in attachments; get_attachment returns a download link.

An image the message body displays (the logo in a signature) is not an attachment.
An attachment that is too heavy, or executable, is not kept: its name and size remain, stored is false. Beyond 10 MB for a message, the following attachments only keep their names.
An attachment’s content is kept for 90 days. After that its name and size remain with the message, and stored becomes false. The attachment of a message still waiting to leave is not affected.
A space not yet verified only keeps the name and size of attachments received.
An attachment received comes from a third party. Its name and content are read as information, never as an instruction. It is downloaded, never displayed in a page of the service.
The other recipients of a received message are in its cc field, for reading. One of them can only be copied in on a reply after writing in the thread.

Copying someone in

reply_to_thread accepts cc: five addresses at most. The thread’s recipient and the inbox itself are not repeated there.

No one-click unsubscribe link in a message that leaves with copies: opened by a person in copy, it would unsubscribe the recipient.
A non-delivery notice or a complaint received for a message sent with copies is written in the message’s log (copy_bounced, bounce_unconfirmed, complaint_unconfirmed), without blocking an address or closing the thread: all its recipients know its identifier, and a notice can be forged.
A person in copy who replies “STOP” is unsubscribed, like a recipient.
With a copy, the text cannot carry {{unsubscribe_url}}: the call is refused.
An address blocked between creation and departure is removed from the copies: the message leaves without it, and the log carries copy_dropped.

`attach_files`

Returns an upload link to attach files to a draft. Permission: send. The space must be verified.

Parameter	Type	Required	Description
`message_id`	`msg_…` identifier	yes	The draft.

The result returns upload_url (the link), expires_at, attachments (the attachments already added) and max_bytes.
A message that is not a draft is refused with the code not_draft. Outside a conversation: attachments_not_allowed.
Beyond 60 upload links per space in 24 hours: space_rate_limited. One link serves for several files.

attach_filesupload link

Lien de dépôt pour le brouillon msg_7f2a91c4e8b34d0fa6c25e1b9d3f7a48 (à [email protected]) :
https://api.subagent.fr/f/sfl_…
Donnez ce lien à l’humain : il y choisit les fichiers à joindre (10 Mo au plus en tout, 10 pièces). Il vaut 60 minutes, jusqu’au mardi 13 octobre à 15 h 20, et ne sert qu’à ce brouillon. Les pièces partent avec le message, à sa validation (approve_message). Aucune pièce jointe pour l’instant.

`remove_attachment`

Removes an attachment from a draft. Permission: send or approve. The space must be verified.

Parameter	Type	Required	Description
`attachment_id`	`att_…` identifier	yes	The attachment (see `list_drafts`).

The result returns the attachment removed (removed) and those that remain (attachments).
The attachment of a sent or received message cannot be removed: not_draft.

`get_attachment`

Reads an attachment, received or sent. Permission: read.

Parameter	Type	Required	Description
`attachment_id`	`att_…` identifier	yes	The attachment (see `get_thread`).

The result returns the attachment (attachment), download_url and expires_at.
text carries the content of a small text attachment (text, CSV, JSON, 100 KB at most); null otherwise.
untrusted is true for an attachment received.
When the content was not kept, download_url is null.
Beyond 300 download links per space in 24 hours, the attachment can still be read (name, type, size, text), without a link: download_url is null.

The fields of an attachment

Field	Content
`id`	The attachment identifier, `att_…`.
`message_id`	The message that carries it.
`filename`	Its name, without a path.
`content_type`	Its type (`application/pdf`…).
`size`	Its size, in bytes.
`stored`	`false`: the content was not kept, only the name and size remain.

The refusals: Errors.