# Encrypted email format

When you encrypt an email with Seald, it is transformed into an attached file, in the .seald_mail format. This format is simply an HTML (opens new window) file, encapsulating the content of the email, in the following format:

  "subject": "Subject of the message",
  "from": "hello@seald.io",
  "to": [
  "date": "Monday October 30th 2017",
  "mailBody": "<html><body><div> Content of the email in the rich-text HTML format <br><br></div></body></html>"

This JSON is then encrypted like any Seald file, in the shtml format.

# Automatic detection in Seald integrations

Integrations for mail clients react to the presence of an attachment with the extension .seald_mail.shtml. The file name is not taken into account, only its extension counts.

If an attachment in the .seald_mail.shtml format is found, it will be automatically decrypted and its mailBody will replace the content of the email.

# Attachments integrated in the mail body

Seald integrations manage mail with images integrated directly in the body of the mail. To do this, the images must be encrypted separately, in the .shtml format, and sent as an attachment along with the mail body in the .seald_mail.shtml format.

To be decrypted and reintegrated into the mail body automatically, the images must be referenced in the mailBody with a tag. The tags contained in the mail body must be of the form:



  • IMAGE_WIDTH: the width of the image;
  • IMAGE_HEIGHT: the height of the image;
  • ATTACHMENT_NAME: the name of the encrypted image attached.