Connection Refused Error: [Errno 111] Connection refused - Getting error for Mailtrap SMTP

Question

I am trying to register user which should send activation code to the dummy server. But while sending the post request from the Insomnia getting 500 internal error.

And using Djoser for the email communication (authentication and authorization)

Error:

...django/core/mail/backends/smtp.py", line 80, in open
    self.connection = self.connection_class(
  File "/usr/lib/python3.10/smtplib.py", line 255, in __init__
    (code, msg) = self.connect(host, port)
  File "/usr/lib/python3.10/smtplib.py", line 341, in connect
    self.sock = self._get_socket(host, port, self.timeout)
  File "/usr/lib/python3.10/smtplib.py", line 312, in _get_socket
    return socket.create_connection((host, port), timeout,
  File "/usr/lib/python3.10/socket.py", line 845, in create_connection
    raise err
  File "/usr/lib/python3.10/socket.py", line 833, in create_connection
    sock.connect(sa)
ConnectionRefusedError: [Errno 111] Connection refused
[22/Jan/2024 20:26:13] "POST /api/v1/auth/users/ HTTP/1.1" 500 144866

Checked telnet to the smtp server

telnet sandbox.smtp.mailtrap.io 2525
Trying 54.158.84.126...
Connected to mailsend-smtp-classic-f3a4534c019a3e96.elb.us-east-1.amazonaws.com.
Escape character is '^]'.
220 smtp.mailtrap.io ESMTP ready

Backend settings

EMAIL_HOST=sandbox.smtp.mailtrap.io
EMAIL_PORT=2525


EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
EMAIL = env("EMAIL_HOST")
EMAIL_USE_TLS = True
EMAIL_PORT = env("EMAIL_PORT")
EMAIL_HOST_USER = env("EMAIL_HOST_USER")
EMAIL_HOST_PASSWORD = env("EMAIL_HOST_PASSWORD")
DAFAULT_FROM_EMAIL = "XXXX"
DOMAIN = env("DOMAIN")
SITE_NAME = "XXXX"

DJOSER = {
    "LOGIN_FIELD": "email",
    "USER_CREATE_PASSWORD_RETYPE": True,
    "USERNAME_CHANGED_EMAIL_CONFIRMATION": True,
    "PASSWORD_CHANGED_EMAIL_CONFIRMATION": True,
    "SEND_CONFIRMATION_EMAIL": True,
    "PASSWORD_RESET_CONFIRM_URL": "password/reset/confirm/{uid}/{token}",
    "SET_PASSWORD_RETYPE": True,
    "PASSWORD_RESET_CONFIRM_RETYPE": True,
    "USERNAME_RESET_CONFIRM_URL": "email/confirm/{uid}/{token}",
    "ACTIVATION_URL":"activate/{uid}/{token}",
    "SEND_ACTIVATION_EMAIL": True,
}

Not sure what is missing piece.