Send Email

Learn how to send messages with postpress.

Feature available for: Google, Microsoft, IMAP.

Send an email

Use the POST /emails method, or use the appropriate SDK method, to send an email to every recipient.

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id=kzAxdybMQ7ipVxK1U6kwZw \
  --form 'subject=Hello from postpress' \
  --form 'body=Hello, this is a test email from postpress' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'cc=[
    {
      "display_name": "Jane Doe",
      "identifier": "jane.doe@gmail.com"
    }
  ]'

Send attachments

You can provide an additional attachments field in the request body to send attachments along with your email.

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id=kzAxdybMQ7ipVxK1U6kwZw \
  --form 'subject=Hello from postpress' \
  --form 'body=Hello, this is a test email from postpress' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'attachments=@C:\Documents\cute_dog.png'

Send with custom headers

You can set additional custom headers using the "X-" syntax.

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id=kzAxdybMQ7ipVxK1U6kwZw \
  --form 'subject=Hello from postpress' \
  --form 'body=Hello, this is a test email from postpress' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'cc=[
    {
      "display_name": "Jane Doe",
      "identifier": "jane.doe@gmail.com"
    }
  ]' \
  --form 'custom_headers=[
    {
      "name": "X-My-Custom-Header",
      "value": "Example value"
    }
  ]'

Reply to an email

You can set the additional parameter reply_to with the provider_id of an email.

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id=kzAxdybMQ7ipVxK1U6kwZw \
  --form 'subject=Re: Hello from postpress' \
  --form 'body=Hello, this is a test reply from postpress' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'reply_to=X4R9___qXQKIu80oAF0lJA'

When replying to an email you can either reply with the exact same subject or add one of the following prefixes followed by a space: Re:, Re :, RE:, RE :, re:, re :.

Personalize "from"

You can set the additional parameter from with your display name and/or alias configured on your provider.

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id=kzAxdybMQ7ipVxK1U6kwZw \
  --form 'subject=Hello from postpress' \
  --form 'body=Hello, this is a test email from postpress' \
  --form 'from={
    "display_name": "Jake Doe",
    "identifier": "myalias.doe@mycompany.com"
  }' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'cc=[
    {
      "display_name": "Jane Doe",
      "identifier": "jane.doe@gmail.com"
    }
  ]'

Tracking options

You can receive a webhook when an email is read or a link is clicked.

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id=kzAxdybMQ7ipVxK1U6kwZw \
  --form 'subject=Hello from postpress' \
  --form 'body=Hello, this is a test email from postpress' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'cc=[
    {
      "display_name": "Jane Doe",
      "identifier": "jane.doe@gmail.com"
    }
  ]' \
  --form 'tracking_options={
    "opens": true,
    "links": true,
    "label": "myownid"
  }'

Send a plain text email

curl --request POST \
  --url https://api.postpress.ai/api/v1/emails \
  --header 'Content-Type: multipart/form-data' \
  --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \
  --form account_id={YOUR_ACCOUNT_ID} \
  --form 'subject=Hello from postpress' \
  --form-string $'body=Hello,\n\nthis is a plain text email from postpress' \
  --form 'to=[
    {
      "display_name": "John Doe",
      "identifier": "john.doe@gmail.com"
    }
  ]' \
  --form 'cc=[
    {
      "display_name": "Jane Doe",
      "identifier": "jane.doe@gmail.com"
    }
  ]' \
  --form-string 'custom_headers=[{"name": "Content-Type", "value": "text/plain; charset=utf-8"}]'

Updated May 2026