Reply to Thread Email
POST
/
inboxes
/
:inbox_id
/
threads
/
:thread_id
/
emails
/
:email_id
/
reply
import { Resend } from 'resend';
const resend = new Resend('re_xxxxxxxxx');
const { data, error } = await resend.inboxes.threads.emails.reply({
inboxId: 'b3e2b2b6-3f0e-4c8e-9ad3-2f43a1e2c7f1',
threadId: '4d8e2a1c-9b3f-4c6d-8a21-3e5f7c9c0d12',
emailId: '5b1a9f47-2c8d-4e6f-9a03-1d2e3f4a5b60',
html: '<p>Refund issued for order 1041.</p>',
text: 'Refund issued for order 1041.',
});curl -X POST 'https://api.resend.com/inboxes/b3e2b2b6-3f0e-4c8e-9ad3-2f43a1e2c7f1/threads/4d8e2a1c-9b3f-4c6d-8a21-3e5f7c9c0d12/emails/5b1a9f47-2c8d-4e6f-9a03-1d2e3f4a5b60/reply' \
-H 'Authorization: Bearer re_xxxxxxxxx' \
-H 'Content-Type: application/json' \
-d $'{
"html": "<p>Refund issued for order 1041.</p>",
"text": "Refund issued for order 1041."
}'resend inboxes threads emails reply \
--inbox_id b3e2b2b6-3f0e-4c8e-9ad3-2f43a1e2c7f1 \
--thread_id 4d8e2a1c-9b3f-4c6d-8a21-3e5f7c9c0d12 \
--email_id 5b1a9f47-2c8d-4e6f-9a03-1d2e3f4a5b60 \
--html "<p>Refund issued for order 1041.</p>" \
--text "Refund issued for order 1041."{
"id": "6a0c8e58-3d9e-4f7a-8b14-2e3f4a5b6c71",
"email_id": "6a0c8e58-3d9e-4f7a-8b14-2e3f4a5b6c71",
"direction": "outbound",
"from": "support@example.com",
"to": ["Ada Lovelace <ada@example.org>"],
"cc": [],
"bcc": [],
"reply_to": [],
"subject": "Re: Refund for order 1041",
"message_id": null,
"html": "<p>Refund issued for order 1041.</p>",
"text": "Refund issued for order 1041.",
"attachments": [],
"read": true,
"received_at": "2026-08-05T14:12:04.110Z"
}Replies from the inbox address. Recipients are taken from the message you reply to. At least one of html or text is required.
Path Parameters
Section titled “Path Parameters”Body Parameters
Section titled “Body Parameters”string
The HTML body.
string
The plain-text body.
string
The subject of the reply. When omitted, the thread subject is used, prefixed with Re: if it isn’t already.
Response Fields
Section titled “Response Fields”string
The ID of the queued outbound email.
string
The ID of the queued outbound email. Same value as id.
string
Always outbound.
string
Sender email address.
string[]
The recipients of the message.
string[]
The CC recipients of the message.
string[]
The BCC recipients of the message.
string[]
Always an empty array.
string
The subject of the sent reply.
string | null
Always null.
string | null
The HTML body.
string | null
The plain-text body.
array
The attachments on the message.
Hide properties
string
The ID of the attachment.
string | null
The filename of the attachment.
number | null
The size of the attachment in bytes.
boolean
Whether the message has been read.
string
ISO 8601 timestamp when the message was sent.
import { Resend } from 'resend';
const resend = new Resend('re_xxxxxxxxx');
const { data, error } = await resend.inboxes.threads.emails.reply({
inboxId: 'b3e2b2b6-3f0e-4c8e-9ad3-2f43a1e2c7f1',
threadId: '4d8e2a1c-9b3f-4c6d-8a21-3e5f7c9c0d12',
emailId: '5b1a9f47-2c8d-4e6f-9a03-1d2e3f4a5b60',
html: '<p>Refund issued for order 1041.</p>',
text: 'Refund issued for order 1041.',
});curl -X POST 'https://api.resend.com/inboxes/b3e2b2b6-3f0e-4c8e-9ad3-2f43a1e2c7f1/threads/4d8e2a1c-9b3f-4c6d-8a21-3e5f7c9c0d12/emails/5b1a9f47-2c8d-4e6f-9a03-1d2e3f4a5b60/reply' \
-H 'Authorization: Bearer re_xxxxxxxxx' \
-H 'Content-Type: application/json' \
-d $'{
"html": "<p>Refund issued for order 1041.</p>",
"text": "Refund issued for order 1041."
}'resend inboxes threads emails reply \
--inbox_id b3e2b2b6-3f0e-4c8e-9ad3-2f43a1e2c7f1 \
--thread_id 4d8e2a1c-9b3f-4c6d-8a21-3e5f7c9c0d12 \
--email_id 5b1a9f47-2c8d-4e6f-9a03-1d2e3f4a5b60 \
--html "<p>Refund issued for order 1041.</p>" \
--text "Refund issued for order 1041."{
"id": "6a0c8e58-3d9e-4f7a-8b14-2e3f4a5b6c71",
"email_id": "6a0c8e58-3d9e-4f7a-8b14-2e3f4a5b6c71",
"direction": "outbound",
"from": "support@example.com",
"to": ["Ada Lovelace <ada@example.org>"],
"cc": [],
"bcc": [],
"reply_to": [],
"subject": "Re: Refund for order 1041",
"message_id": null,
"html": "<p>Refund issued for order 1041.</p>",
"text": "Refund issued for order 1041.",
"attachments": [],
"read": true,
"received_at": "2026-08-05T14:12:04.110Z"
}Was this page helpful?
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