Flask-Mail ssl.SSLError: [SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:997)

Question

I'm developing a service to send email to user to recover password. But, when I make a request to a given endpoint to call this function, I receive ssl.SSLError: [SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:997).

I'm using MailTrap in development and my environment variables are written in .env file like this:

MAIL_SERVER="sandbox.smtp.mailtrap.io"
MAIL_PORT=2525
MAIL_USERNAME="my_username"
MAIL_PASSWORD="my_password"
MAIL_USE_SSL=false
MAIL_USE_TLS=true

This is a default configuration provided by MailTrap to be used in Flask-Mail.

I tried use other values for MAIL_PORT, MAIL_USE_SSL, MAIL_USE_TLS, like:

MAIL_PORT=587
MAIL_USE_SSL=false
MAIL_USE_TLS=true

and

MAIL_PORT=465
MAIL_USE_SSL=true
MAIL_USE_TLS=false

but nothing was enough.

Code used to send email is:

from flask import current_app, render_template
from flask_mail import Message

from gymanager.extensions.mailer import mail


def send_mail(subject, to, template, **kwargs):
    msg = Message(
        subject=subject,
        recipients=[to],
        sender=current_app.config["MAIL_SENDER"]
    )

    msg.body = render_template(f"mails/{template}.txt", **kwargs)
    msg.html = render_template(f"mails/{template}.html", **kwargs)

    mail.send(msg)

Resource that calls the function above:

import secrets
from flask_restful import Resource, reqparse

from gymanager.models import User
from gymanager.extensions.database import db
from gymanager.services.mail import send_mail

from werkzeug.security import generate_password_hash

class ForgetPassword(Resource):
    def post(self):
        parser = reqparse.RequestParser(trim=True)
        parser.add_argument("email", required=True, help="required field")
        args = parser.parse_args()

        user = User.query.filter_by(email=args.email).first()
        if not user:
            return {"error": "user not found"}, 400
        
        password_temp = secrets.token_hex(8)
        user.password = generate_password_hash(password_temp)
        
        db.session.add(user)

        try:
            db.session.commit()
        except Exception as e:
            db.session.rollback()
            return {"error": "could not possible reset password"}, 500
        
        send_mail(
            subject="recuperação da conta",
            to=user.email,
            template="forget-password",
            password_temp=password_temp
        )

        return {"msg": "email sended successfully"}, 201

This resource is called by an endpoint.

How I solve this issue?