smtp module does not send HELO/EHLO after STARTTLS

[mildred]

Using the provided example of the smtp module:

Example

import smtp

type
  SmtpConfig* = ref object
    server*: string
    port*: int
    user*: string
    pass*: string
    debug*: bool
    sender*: string

proc send_email(cfg: SmtpConfig, sender, recipient: string, msg: Message) =
  let smtpConn = newSmtp(debug=cfg.debug)
  let port = Port(if cfg.port == 0: 25 else: cfg.port)
  smtpConn.connect(cfg.server, port)
  #smtpConn.startTls()
  echo $cfg.user
  if cfg.user != "":
    smtpConn.auth(cfg.user, cfg.pass)
  smtpConn.sendMail(sender, @[recipient], $msg)

When STARTTLS is enabled, the smtp client fails to send EHLO once the secure connexion is established. Here is the protocol

Current Output

log:

C:HELO mailu.mildred.fr

S:250 ellomb.netlib.re
C:STARTTLS

S:220 2.0.0 Start TLS
C:AUTH LOGIN

S:334 VXNlcm5hbWU6
C:bmltbmV3c0Bib3VyZGVyaWUubWlsZHJlZC5mcg==

S:334 UGFzc3dvcmQ6
C:bmltbmV3c0Bib3VyZGVyaWUubWlsZHJlZC5mcg=

S:235 2.0.0 OK
C:MAIL FROM:<nimnews@bourderie.mildred.fr>

S:503 5.5.1 Error: send HELO/EHLO first
C:QUIT

Expected Output

EHLO after STARTTLS

Additional Information

$ nim -v
Nim Compiler Version 1.2.4 [Linux: amd64]
Compiled at 2020-06-26
Copyright (c) 2006-2020 by Andreas Rumpf

active boot switches: -d:release