gomap

Go module for interfacing with JMAP mail servers, such as Fastmail.

Usage

To add the module to your project:

go get -u github.com/cwinters8/gomap

First, create a new mail client. You will need a session URL and a bearer token from your JMAP mail server. For Fastmail, the session URL is https://api.fastmail.com/jmap/session, and you can create an API token in Settings > Privacy & Security > Integrations > API tokens. You will most likely need to give access to Email (for querying and reading email contents) and Email submission (for sending emails) when you create the token.

mail, err := gomap.NewClient(
  "https://api.fastmail.com/jmap/session",
  os.Getenv("BEARER_TOKEN"),
  gomap.DefaultDrafts,
  gomap.DefaultSent,
)
if err != nil {
  log.Fatal(err)
}

Then you can use the client for your chosen operations. Check out the examples for full details on how to send and find emails.

Sending with a custom visible From address

JMAP requires every EmailSubmission to be associated with an account Identity, but the message's visible From header is part of the Email object. Use SendEmailWithIdentity when those values need to differ, such as contact-form notifications where the visible sender should be the email address submitted in the form while the authenticated mailbox identity is used for submission:

submitter := gomap.NewAddress("Form Submitter", "submitter@example.com")
recipient := gomap.NewAddress("Contact Inbox", "contact@example.org")

err := mail.SendEmailWithIdentity(
  gomap.NewAddresses(submitter),
  gomap.NewAddresses(recipient),
  "Contact form submission",
  "Message body",
  "administrator@example.org", // authenticated JMAP identity email
  false,
)

Servers may still reject this if the selected identity is not permitted to use the requested From header.