Email (SMTP)¶

(kaappi email) — send email via SMTP with TLS and authentication.

thottam install kaappi-email

Depends on kaappi-net (auto-installed).

Quick start¶

(import (kaappi email))

(send-email "smtp.gmail.com" 465
  "you@gmail.com"
  '("recipient@example.com")
  "Hello from Kaappi!"
  "This email was sent from Kaappi Scheme."
  'tls #t
  'user "you@gmail.com"
  'password "your-app-password"
  'domain "gmail.com")

High-level API¶

`send-email`¶

(send-email host port from to subject body [options...])

Parameter	Type	Description
`host`	string	SMTP server hostname
`port`	integer	SMTP port (465 for TLS, 587 for STARTTLS, 25 for plain)
`from`	string	Sender email address
`to`	list	List of recipient email addresses
`subject`	string	Email subject line
`body`	string	Email body text

Options¶

Option	Type	Description
`'tls`	boolean	Use TLS connection (port 465)
`'user`	string	SMTP username for authentication
`'password`	string	SMTP password
`'domain`	string	EHLO domain
`'cc`	list	CC recipients

Send to multiple recipients¶

(send-email "smtp.example.com" 465
  "sender@example.com"
  '("alice@example.com" "bob@example.com")
  "Team Update"
  "Here is the weekly update."
  'tls #t
  'user "sender@example.com"
  'password "password"
  'cc '("manager@example.com"))

Message construction¶

Build messages without sending them — useful for testing or custom delivery:

(import (kaappi email mime))

(define msg
  (make-message
    "sender@example.com"
    '("recipient@example.com")
    "Test Subject"
    "Hello, world!"))

(display (message->string msg))

The (kaappi email mime) sub-library handles message construction independently from the network layer.

Low-level SMTP¶

For full control over the SMTP session:

(import (kaappi email smtp))

(define smtp (smtp-connect-tls "smtp.gmail.com" 465))
(smtp-ehlo smtp "example.com")
(smtp-auth-plain smtp "user@gmail.com" "app-password")

(define msg (make-message "from@example.com" '("to@example.com")
              "Subject" "Body"))
(smtp-send-message smtp msg)

(smtp-close smtp)

SMTP procedures¶

Procedure	Description
`(smtp-connect host port)`	Plain SMTP connection
`(smtp-connect-tls host port)`	TLS SMTP connection
`(smtp-ehlo smtp domain)`	Send EHLO greeting
`(smtp-auth-plain smtp user pass)`	PLAIN authentication
`(smtp-send-message smtp msg)`	Send a constructed message
`(smtp-close smtp)`	Close connection

Provider setup¶

Gmail¶

Use an App Password (not your regular password):

(send-email "smtp.gmail.com" 465
  "you@gmail.com" '("to@example.com")
  "Subject" "Body"
  'tls #t
  'user "you@gmail.com"
  'password "your-16-char-app-password"
  'domain "gmail.com")

Amazon SES¶

(send-email "email-smtp.us-east-1.amazonaws.com" 465
  "verified@yourdomain.com" '("to@example.com")
  "Subject" "Body"
  'tls #t
  'user "AKIAIOSFODNN7EXAMPLE"
  'password "ses-smtp-password"
  'domain "yourdomain.com")

Local / development¶

For testing without authentication:

(send-email "localhost" 1025
  "test@localhost" '("dev@localhost")
  "Test" "Testing email locally")

Use MailHog or similar for local SMTP testing.

Sub-libraries¶

Library	Purpose
`(kaappi email)`	High-level `send-email`
`(kaappi email mime)`	Message construction (no network)
`(kaappi email smtp)`	Low-level SMTP protocol

Utilities¶

(base64-encode "hello")  ;=> "aGVsbG8="

API reference¶

High-level¶

Procedure	Description
`(send-email host port from to subject body [opts])`	Send email

Message¶

Procedure	Description
`(make-message from to subject body [opts])`	Create message
`(message->string msg)`	Render to MIME string

SMTP¶

Procedure	Description
`(smtp-connect host port)`	Plain connection
`(smtp-connect-tls host port)`	TLS connection
`(smtp-ehlo smtp domain)`	EHLO greeting
`(smtp-auth-plain smtp user pass)`	Authenticate
`(smtp-send-message smtp msg)`	Send message
`(smtp-close smtp)`	Close connection