Read a conversation
const url = 'https://mail.work.optidata.cloud/api/mail/mailboxes/78/folders/2/conversations/4185/reader?fetch_message_id=4184';const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};
try { const response = await fetch(url, options); const data = await response.json(); console.log(data);} catch (error) { console.error(error);}curl --request GET \ --url 'https://mail.work.optidata.cloud/api/mail/mailboxes/78/folders/2/conversations/4185/reader?fetch_message_id=4184' \ --header 'Authorization: Bearer <token>'Every message of a thread, each with its rendered, sanitised HTML body and
its attachment list. The order follows the caller’s message order
preference. Pass fetch_message_id to guarantee that one specific message
of the thread comes back with its body expanded.
Authorizations
Section titled “Authorizations”Parameters
Section titled “ Parameters ”Path Parameters
Section titled “Path Parameters”Id of the mailbox. Every mailbox the caller may use is listed in their account.
Id of the folder, as returned by GET /folders.
Id of the conversation, exactly as returned by a listing.
Query Parameters
Section titled “Query Parameters”Id of the message whose body must be expanded.
Responses
Section titled “ Responses ”The messages of the thread, in reading order.
A message together with its rendered, sanitised HTML body.
object
A message as it appears inside a listing or a thread.
object
The RFC 5322 Message-ID header.
The state of a message or thread, as a set of booleans.
object
The user starred it.
It carries a calendar invitation.
A read receipt was requested.
The addresses of a message, grouped by role.
object
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
One participant of a message.
object
Display name, when one is known.
The role the address plays: f sender, t recipient, c carbon copy,
b blind copy, r reply-to.
Left empty in listings; read the body with a reader operation.
A file carried by a message.
object
MIME part number, used to download it.
The cid an inline image is referenced by inside the body.
attachment or inline.
Position used to name a file that arrived without one.
Icon hint for a file-type badge.
Signed download link, populated by the reader operations. Use it as-is.
A file carried by a message.
object
MIME part number, used to download it.
The cid an inline image is referenced by inside the body.
attachment or inline.
Position used to name a file that arrived without one.
Icon hint for a file-type badge.
Signed download link, populated by the reader operations. Use it as-is.
The calendar invitation carried by the message, when there is one.
The folder-sharing offer carried by the message, when there is one.
Sanitised HTML, ready to render.
Examples
[ { "body": "<div>Thanks — attaching the signed copy.</div>", "message": { "id": "4184", "date": "2026-08-19T12:43:02.000000Z", "subject": "Re: Quarterly report", "fragment": "Thanks — attaching the signed copy…", "conversationId": "4185", "messageIdHeader": "<790852736.20477.1787149382@mail.example>", "sizeBytes": 6972669, "folderId": "2", "body": [], "tagIds": [], "invite": null, "share": null, "inlineAttachments": [], "attachments": [], "flags": { "isUnread": false, "isFlagged": false, "hasAttachment": true, "isReplied": false, "isSentByMe": true, "isForwarded": false, "isInvite": false, "isDraft": false, "isDeleted": false, "isNotificationSent": false, "isUrgent": false, "isLowPriority": false, "isPriority": false }, "participants": { "from": [ { "name": "Jane Doe", "email": "jane.doe@acme.example", "type": "f" } ], "to": [ { "name": "John Roe", "email": "john.roe@example.com", "type": "t" } ], "cc": [], "bcc": [], "replyTo": [], "sender": [], "notification": [], "resentFrom": [] } } }]Missing, malformed or expired authentication key.
Authentication failures use an error key rather than message.
object
Examples
No bearer token sent
{ "error": "JWT passport exception: Missing bearer token in request"}The caller may not act on this mailbox, user or resource.
Generic error envelope used by policy, binding and framework failures.
object
Human-readable description of the failure.
Examples
{ "message": "This action is unauthorized."}The request body or query string failed validation.
object
The first validation message.
Validation messages keyed by field name.
object
Examples
{ "message": "The conversations field is required.", "errors": { "conversation_ids": [ "The conversations field is required." ] }}Rate limit exceeded. Retry after the window resets.
Generic error envelope used by policy, binding and framework failures.
object
Human-readable description of the failure.
Examples
{ "message": "Too Many Attempts."}The mail platform did not answer as expected — a folder or message that
does not exist, or a transient failure. reference is the code to quote to
support and fault_code names the underlying condition. A 503 with the
same envelope means the platform is in maintenance; retry shortly.
Failure raised by the mail platform behind the API rather than by the request itself.
object
What went wrong, phrased for the end user.
Repeats the HTTP status code.
Suggested next step.
Support reference, e.g. MZ-502.
Names the underlying condition, e.g. mail.NO_SUCH_FOLDER.
Examples
Unknown folder
{ "error": "The mail server did not answer as expected, so this action could not be completed.", "status": 502, "help": "If the problem persists, contact support and inform the error code above.", "reference": "MZ-502", "fault_code": "mail.NO_SUCH_FOLDER"}Unknown message
{ "error": "The mail server did not answer as expected, so this action could not be completed.", "status": 502, "help": "If the problem persists, contact support and inform the error code above.", "reference": "MZ-502", "fault_code": "mail.NO_SUCH_MSG"}