backend-collector/app/dependencies/mail.py

from fastapi_mail import ConnectionConfig
from pathlib import Path
import os

conf = ConnectionConfig(
    MAIL_USERNAME = os.environ["MAILER_USERNAME"],
    MAIL_PASSWORD = os.environ["MAILER_PASSWORD"],
    MAIL_FROM = os.environ["MAILER_FROM"],
    MAIL_PORT = os.environ["MAILER_PORT"],
    MAIL_SERVER = os.environ["MAILER_HOST"],
    MAIL_STARTTLS = True,
    MAIL_SSL_TLS = False,
    TEMPLATE_FOLDER = Path(__file__).parents[1] / 'templates',
)