Replies and threads

Answer emails so they stay in the same conversation.

Reply to an email

Pass the email_… id of the email you’re answering as reply_to:

curl -X POST "$EE_URL/api/v1/emails" \
  -H "X-API-KEY: $EE_KEY" -H "Content-Type: application/json" \
  -d '{
    "account_id": "acc_ba1fa6938d8548298e8ce62e4b4b4e99",
    "reply_to": "email_94a0d77db739407e932c3b97fef44aac",
    "body": "<p>Thanks, looks good!</p>"
  }'

Response 201

{ "object": "EmailSent", "account_id": "acc_ba1fa6938d8548298e8ce62e4b4b4e99", "message_id": "[e-mail]", "provider_id": null, "tracking_id": null }

The engine fills in the rest:

	Default
Recipients	The original’s Reply-To, or its sender, when you give no to/cc/bcc
Subject	Re: plus the original subject, when you give none
In-Reply-To	The original’s Message-ID
References	The original’s references plus its Message-ID

So the reply shows in the same conversation in Gmail and other email clients, for the user and the recipients.

reply_to must be an email of the same account that the engine has synced. Emails that arrived before the account connected aren’t synced, so they can’t be answered this way. An unknown reply_to gets 400 errors/invalid_parameters.

To reply to everyone, pass the recipients yourself, for example the original from_attendee plus its to_attendees and cc_attendees, minus the user’s own address.

Find the email a reply answers

Every email has in_reply_to:

"in_reply_to": { "message_id": "[e-mail]", "id": "email_5b1e9a2c3d4f4e6a8b7c0d1e2f3a4b5c" }

id is the email_… id of the answered email when the account has it, so you can fetch it with GET /api/v1/emails/{id}. It’s null when the account doesn’t have it, for example when it arrived before the account connected. in_reply_to is null for emails that answer nothing.

Forward

There’s no separate forward call. Send a new email with the original’s body and attachments. Download the attachments with the attachment endpoint and attach them again.

Threads

Every email has a thread_id:

Provider	thread_id
IMAP (Gmail included)	The Message-ID of the conversation’s first email, found through References and In-Reply-To

List a whole conversation, newest first:

curl "$EE_URL/api/v1/emails?thread_id=1a11078796ab3f43" -H "X-API-KEY: $EE_KEY"

The response is an Emails list ({ "object": "Emails", "data": [...], "has_more": false, "cursor": null }).