Send messages with Nylas

Nylas offers multiple ways to send messages. This page describes how to choose the best method for your project, how to create and send a draft, and how to send a message without creating a draft.

Choose how to send messages

Nylas offers two different ways to send messages:

Create and send a draft: This method is ideal for preparing messages that you don’t need to send immediately. Nylas syncs drafts to the provider’s Draft folder, if possible.
Send message without creating draft: This method is ideal for sending a small number of messages without saving them as drafts first. Nylas syncs messages to the provider’s Sent folder, if possible.

In both cases, the sending operation is synchronous (meaning Nylas sends items one at a time) and the request blocks until the submission either succeeds or fails. If the submission fails, Nylas does not automatically try to send the message again. For more information, see Deliverability for drafts and Send endpoint.

When you make a Send Message request, Nylas connects to the provider to send the message as the user. Because of this, providers see the activity as the user sending a message, rather than an external platform making the request on the user’s behalf.

Messages sent through Nylas have very high deliverability, but might be subject to rate-limiting and abuse detection from the provider. See Improve email deliverability for more information and a list of best practices.

Create and send a draft

If you want to prepare a message that you don’t need to send immediately, you can create a draft and send it later. When you create a draft with Nylas, it’s synced with the provider. You can access it and make updates as long as it isn’t deleted.

To create a draft in Nylas v3, make a Create Draft request and include any relevant information, or use the Nylas SDKs. If you make the request with no parameters, Nylas creates a draft with no content.

curl --request POST \
  --url https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/drafts \
  --header 'Authorization: Bearer <NYLAS_API_KEY>' \
  --header 'Content-Type: application/json' \
  --data '{
  "subject": "From Nylas",
  "to": [
    {
      "email": "[email protected]",
      "name": "Dorothy Vaughan"
    }
  ],
  "cc": [
    {
      "email": "George Washington Carver",
      "name": "[email protected]"
    }
  ],
  "bcc": [
    {
      "email": "Albert Einstein",
      "name": "[email protected]"
    }
  ],
  "reply_to": [
    {
      "email": "[email protected]",
      "name": "Stephanie Kwolek"
    }
  ],
  "body": "This email was sent using the Nylas email API. Visit https://nylas.com for details.",
  "tracking_options": {
    "opens": true,
    "links": true,
    "thread_replies": true,
    "label": "hey just testing"
 }
}'

import 'dotenv/config'
import Nylas from 'nylas'

const NylasConfig = {
  apiKey: process.env.NYLAS_API_KEY,
  apiUri: process.env.NYLAS_API_URI,
}

const nylas = new Nylas(NylasConfig)
const identifier = process.env.NYLAS_GRANT_ID

const createDraft = async () => {
  try {
    const draft = {
      subject: "Your Subject Here",
      to: [{ name: "Recipient Name", email: "[email protected]" }],
      body: "Your email body here.",
    }

    const createdDraft = await nylas.drafts.create({
        identifier,
        requestBody: draft
    })

    console.log('Draft created:', createdDraft)

  } catch (error) {
    console.error('Error creating draft:', error)
  }
}

createDraft()

import os
import sys
from nylas import Client
from nylas import utils

nylas = Client(
    "<NYLAS_API_KEY>",
    "<NYLAS_API_URI")
)

grant_id = "<NYLAS_GRANT_ID>"
email = "<EMAIL>"

attachment = utils.file_utils.attach_file_request_builder("Nylas_Logo.png")

draft = nylas.drafts.create(
  grant_id,
  request_body={
    "to": [{ "name": "Name", "email": email }],
    "reply_to": [{ "name": "Name", "email": email }],
    "subject": "Your Subject Here",
    "body": "Your email body here.",
    "attachments": [attachment]
  }
)

print(draft)

require 'nylas'

# Initialize Nylas client
nylas = Nylas::Client.new(
  api_key: "<NYLAS_API_KEY>"
)

file = Nylas::FileUtils.attach_file_request_builder("Nylas_Logo.png")

request_body = {
    subject: "From Nylas",
    body: 'This email was sent using the ' +
              'Nylas email API. ' +
              'Visit https://nylas.com for details.',
    to: [{ name: "Dorothy Vaughan",
            email: "[email protected]"}],
    cc: [{ name: "George Washington Carver",
            email: "[email protected]"}],
    bcc: [{ name: "Albert Einstein",
            email: "[email protected]"}],
    reply_to: [{ name: "Stephanie Kwolek",
            email: "[email protected]"}],
   tracking_options: {label: "hey just testing",
        opens: true,
        links: true,
        thread_replies: true},
   attachments: [file]
}

draft, _ = nylas.drafts.create(identifier: "<NYLAS_GRANT_ID>", request_body: request_body)
puts "Draft \"#{draft[:subject]}\" was created with ID: #{draft[:id]}"

import com.nylas.NylasClient;
import com.nylas.models.*;
import com.nylas.util.FileUtils;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class CreateDraft {
  public static void main(String[] args) throws NylasSdkTimeoutError, NylasApiError {
    NylasClient nylas = new NylasClient.Builder("<NYLAS_API_KEY>").build();

    CreateAttachmentRequest attachment = FileUtils.attachFileRequestBuilder("src/main/java/Nylas_Logo.png");
    List<CreateAttachmentRequest> request = new ArrayList<>();
    request.add(attachment);

    CreateDraftRequest requestBody = new CreateDraftRequest.Builder().
        to(Collections.singletonList(new EmailName("[email protected]", "Nylas"))).
        cc(Collections.singletonList(new EmailName("[email protected]", "Dorothy Vaughan"))).
        bcc(Collections.singletonList(new EmailName("[email protected]", "Hedy Lamarr"))).
        subject("With Love, from Nylas").
        body("This email was sent using the Nylas email API. Visit https://nylas.com for details.").
        attachments(request).
        build();

    Response<Draft> drafts = nylas.drafts().create(dotenv.get("NYLAS_GRANT_ID"), requestBody);

    System.out.println("Draft " + drafts.getData().getSubject() +
        " was created with ID " + drafts.getData().getId());
  }
}

import com.nylas.NylasClient
import com.nylas.models.*
import com.nylas.util.FileUtils

fun main(args: Array<String>) {
  val nylas: NylasClient = NylasClient(
      apiKey = "<NYLAS_API_KEY>"
  )

  val attachment: CreateAttachmentRequest = FileUtils.attachFileRequestBuilder("src/main/kotlin/Nylas_Logo.png")

  val requestBody = CreateDraftRequest(
      to = listOf(EmailName("[email protected]", "Nylas")),
      cc = listOf(EmailName("[email protected]", "Dorothy Vaughan")),
      bcc = listOf(EmailName("[email protected]", "Hedy Lamarr")),
      subject = "With Love, from Nylas",
      body = "This email was sent using the Nylas Email API. Visit https://nylas.com for details.",
      attachments = listOf(attachment)
  )

  val draft = nylas.drafts().create(dotenv["NYLAS_GRANT_ID"], requestBody).data

  print("Draft " + draft.subject + " was created with ID: " + draft.id)
}

When you’re ready, you can send the draft by making a Send Draft request or by using the SDKs.

curl --request POST \
  --url https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/drafts/<DRAFT_ID>  \
  --header 'Accept: application/json, application/gzip' \
  --header 'Authorization: Bearer <NYLAS_API_KEY>' \
  --header 'Content-Type: application/json' \

import 'dotenv/config'
import Nylas from 'nylas'

const NylasConfig = {
  apiKey: process.env.NYLAS_API_KEY,
  apiUri: process.env.NYLAS_API_URI,
}

const nylas = new Nylas(NylasConfig)
const identifier = process.env.NYLAS_GRANT_ID
const draftId = process.env.DRAFT_ID

const sendDraft = async () => {
  try {
    const sentMessage = await nylas.drafts.send({ identifier, draftId })
    console.log('Draft sent:', sentMessage)
  } catch (error) {
    console.error('Error sending draft:', error)
  }
}

sendDraft()

from dotenv import load_dotenv
load_dotenv()

import os
import sys
from nylas import Client

nylas = Client(
    os.environ.get('NYLAS_API_KEY'),
    os.environ.get('NYLAS_API_URI')
)

grant_id = os.environ.get("NYLAS_GRANT_ID")
draft_id = os.environ.get("DRAFT_ID")

draft = nylas.drafts.send(
  grant_id,
  draft_id
)

print(draft)

import com.nylas.NylasClient

fun main(args: Array<String>) {

    val nylas: NylasClient = NylasClient(
        apiKey = "<NYLAS_API_KEY>"
    )

    val draft = nylas.drafts().send("<NYLAS_GRANT_ID>", "<DRAFT_ID>")
    print(draft.data)
}

import com.nylas.NylasClient;
import com.nylas.models.*;

public class SendDraft {
    public static void main(String[] args) throws
    NylasSdkTimeoutError, NylasApiError {

        NylasClient nylas = new NylasClient.Builder("<NYLAS_API_KEY>").build();

        Response<Message> draft =
        nylas.drafts().send("<NYLAS_GRANT_ID>", "<DRAFT_ID>");
        System.out.println(draft.getData());
    }
}

Create and send a message

If you want to create and send a message immediately, make a Send Message request or use the Nylas SDKs.

curl --request POST \
  --url https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/messages/send \
  --header 'Authorization: Bearer <NYLAS_API_KEY>' \
  --header 'Content-Type: application/json' \
  --data '{
  "subject": "Hey Reaching Out with Nylas",
  "body": "Hey I would like to track this link <a href='https://espn.com'>My Example Link</a>",
  "to": [
    {
      "name": "John Doe",
      "email": "[email protected]"
    }
  ],
  "tracking_options": {
    "opens": true,
    "links": true,
    "thread_replies": true,
    "label": "hey just testing"
  }
}'

import { createFileRequestBuilder } from 'utils';

app.get("/nylas/send-email", async (req, res) => {
  try {
    const file = createFileRequestBuilder("Nylas_Logo.png")
    const sentMessage = await nylas.messages.send({
      identifier: process.env.USER_GRANT_ID,
      requestBody: {
        to: [{ name: "Name", email: process.env.EMAIL }],
        replyTo: [{ name: "Name", email: process.env.EMAIL }],
        replyToMessageId: "<MESSAGE_ID>",
        subject: "Your Subject Here",
        body: "Your email body here.",
        attachments: [file]
      },
    });

    res.json(sentMessage);
  } catch (error) {
    console.error("Error sending email:", error);
  }
});

import os
import sys
from nylas import Client
from nylas import utils

nylas = Client(
    "<NYLAS_API_KEY>",
    "<NYLAS_API_URI>"
)

grant_id = "<NYLAS_GRANT_ID>"
email = "<EMAIL>"

attachment = utils.file_utils.attach_file_request_builder("Nylas_Logo.png")

message = nylas.messages.send(
  grant_id,
  request_body={
    "to": [{ "name": "Name", "email": email }],
    "reply_to": [{ "name": "Name", "email": email }],
    "reply_to_message_id": "<MESSAGE_ID>",
    "subject": "Your Subject Here",
    "body": "Your email body here.",
    "attachments": [attachment]
  }
)

print(message)

import os
import sys
from nylas import Client
from nylas import utils

nylas = Client(
    "<NYLAS_API_KEY>",
    "<NYLAS_API_URI>"
)

grant_id = "<NYLAS_GRANT_ID>"
email = "<EMAIL>"

attachment = utils.file_utils.attach_file_request_builder("Nylas_Logo.png")

message = nylas.messages.send(
  grant_id,
  request_body={
    "to": [{ "name": "Name", "email": email }],
    "reply_to": [{ "name": "Name", "email": email }],
    "reply_to_message_id": "<MESSAGE_ID>",
    "subject": "Your Subject Here",
    "body": "Your email body here.",
    "attachments": [attachment]
  }
)

print(message)

import com.nylas.NylasClient
import com.nylas.models.*
import com.nylas.util.FileUtils

fun main(args: Array<String>) {

    val nylas: NylasClient = NylasClient(
        apiKey = "<NYLAS_API_KEY>"
    )

    val attachment: CreateAttachmentRequest = FileUtils.attachFileRequestBuilder("src/main/kotlin/Nylas_Logo.png")

    val options = TrackingOptions("hey just testing", true, true, true)

    val emailNames : List<EmailName> = listOf(EmailName("[email protected]",
    "John Doe"))
    val requestBody : SendMessageRequest =
    SendMessageRequest.Builder(emailNames).
        subject("Hey Reaching Out with Nylas").
        body("Hey I would like to track this link <a href='https://espn.com'>My Example Link</a>").
        trackingOptions(options).
        attachments(listOf(attachment)).
        build()
    val email = nylas.messages().send("<NYLAS_GRANT_ID>",
    requestBody)
    print(email.data)
}

import com.nylas.NylasClient;
import com.nylas.models.*;
import java.util.ArrayList;
import java.util.List;
import com.nylas.util.FileUtils;

public class SendEmails {
    public static void main(String[] args) throws
    NylasSdkTimeoutError, NylasApiError {
        NylasClient nylas = new NylasClient.Builder("<NYLAS_API_KEY>").build();

        CreateAttachmentRequest attachment = FileUtils.attachFileRequestBuilder("src/main/java/Nylas_Logo.png");
        List<CreateAttachmentRequest> request = new ArrayList<>();
        request.add(attachment);

        List<EmailName> emailNames = new ArrayList<>();
        emailNames.add(new EmailName("[email protected]",
        "John Doe"));

        TrackingOptions options =
        new TrackingOptions("hey just testing", true, true, true);

        SendMessageRequest requestBody =
        new SendMessageRequest.Builder(emailNames).
                trackingOptions(options).
                subject("Hey Reaching Out with Nylas").
                body("Hey I would like to track this link <a href='https://espn.com'>My Example Link</a>.").
                attachments(request).
                build();

        Response<Message> email =
        nylas.messages().send("<NYLAS_GRANT_ID>", requestBody);
        System.out.println(email.getData());
    }
}

Draft deliverability and the Send endpoint

Send operations are synchronous (meaning Nylas sends items one at a time), and the request blocks until the submission succeeds or fails. If the request fails, Nylas does not automatically try to send the message again.

Nylas recommends that you apply a backoff strategy when you receive 503 errors. Your application might need to wait between 10–20 minutes, or else SMTP servers might continue to refuse connections for the affected user.

For information on the number of messages you can send per day, see the Provider rate limits documentation. If large-volume sending continues to fail for your application, Nylas recommends you switch to a transactional sending service (for example, Mailgun, SendGrid, Mandrill, or Amazon SES).

Bounce detection

Nylas monitors for and notifies you when a user gets a message bounce notification. Bounce notifications are sent by a recipient’s provider when the message can’t be delivered, and usually include a detailed error message. When a user receives a notification that a message bounced, Nylas scans it and grabs the cause from the error message.

Messages can bounce for a variety of reasons, and can be considered either “soft” bounces (those with a temporary root cause, like the recipient’s inbox being full) or “hard” bounces (those with a permanent root cause, like the recipient’s email address no longer exists). Currently, Nylas supports hard bounces only, and publishes mailbox_unavailable and domain_not_found bounces. For more information about bounce detection, see the message.bounce_detected notification schema and Soft vs. Hard Bounce - what’s the difference? on the Nylas blog.

The message ID header

Sending a message using the Nylas Email API creates a unique message_id_header in the sender’s database, similar to the example below.

[email protected]

This value is required for the provider’s SMTP server, and is part of the standard protocol when using Nylas as an email client. The header is visible only on the sender’s database, and isn’t an object that you can use or update.

The provider’s SMTP server might change this value during the sending process. Nylas recommends you avoid using this message_id_header with the @mailer.nylas.com domain for email configuration.

Override sender display name

When you send messages using Nylas, you can set the sender’s display name by modifying the from.name parameter in your request.

curl --request POST \
  --url https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/messages/send \
  --header 'Authorization: Bearer <NYLAS_API_KEY>' \
  --header 'Content-Type: application/json' \
  --data '{
    "subject": "Reaching out with Nylas",
    "to": [{
      "name": "Leyah Miller",
      "email": "[email protected]"
    }],
    "from": [{
      "name": "Nyla",
      "email": "[email protected]"
    }]
  }'

If you don’t include the from field when you send a message, Nylas uses the account’s default display name.

Limitations for sending messages

Microsoft Graph and iCloud don’t support the List-Unsubscribe-Post or List-Unsubscribe headers. Because of this, Nylas can’t support these headers for messages sent from Microsoft Graph and iCloud accounts.
Some providers change folders immediately after a message sends successfully (for example, moving the message from the Outbox folder to Sent). Because of this, you might receive multiple message.updated notifications for a single send request.
Nylas automatically de-duplicates some webhook notifications to avoid spam, so you might receive a message.updated notification instead of a message.created notification.