Using tls-extra for simple smtp

Question

I am trying to write a simple script to send a mail via my gmail account. But I am a beginner so it is not that simple. I tryed google but exept for hackage, there is no help or

Answer 1

You could use the connection package which simplify client connection and provide all the necessary bits for this. The following code will works to connect to smtp.gmail.com:

{-# LANGUAGE OverloadedStrings #-}
import qualified Data.ByteString as B
import Data.ByteString.Char8 ()
import Network.Connection
import Data.Default

readHeader con = do
    l <- connectionGetLine 1024 con
    putStrLn $ show l
    if B.isPrefixOf "250 " l
        then return ()
        else readHeader con

main = do
    ctx <- initConnectionContext
    con <- connectTo ctx $ ConnectionParams
                            { connectionHostname  = "smtp.gmail.com"
                            , connectionPort      = 25
                            , connectionUseSecure = Nothing
                            , connectionUseSocks  = Nothing
                            }

    -- read the server banner
    connectionGetLine 1024 con >>= putStrLn . show
    -- say ehlo to the smtp server
    connectionPut con "EHLO\n"
    -- wait for a reply and print
    readHeader con
    -- Tell the server to start a TLS context.
    connectionPut con "STARTTLS\n"
    -- wait for a reply and print
    connectionGetLine 1024 con >>= putStrLn . show

    -- negociate the TLS context
    connectionSetSecure ctx con def

    ------- connection is secure now
    -- send credential, passwords, ask question, etc.

    -- then quit politely.
    connectionPut con "QUIT\n"
    connectionClose con