utils/sendmail.py

#!/usr/bin/env python3


from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders
from os import path
from smtplib import SMTP
from socket import error, create_connection, close
from time import sleep


class Mail:
    """
    Sending email from Python
    """
    def __init__(self, smtp_user: str, smtp_pass: str, mail_dest: str,
                 smtp_host: str = 'smtp.gmail.com', smtp_port: str = '587', smtp_stls: bool = True,
                 mail_from: str = None, mail_subj: str = 'no subject',
                 mail_text: str = 'no text', mail_type: str = 'plain',
                 mail_file: str = None) -> None:
        """
        Object constructor
        :param smtp_user: smtp valid user
        :param smtp_pass: smtp valid password
        :param mail_dest: destination addresses
        :param smtp_host: smtp hostname or ip address
        :param smtp_port: smtp port number
        :param smtp_stls: smtp required tls
        :param mail_from: mail from alias
        :param mail_subj: mail subject
        :param mail_text: mail body text
        :param mail_type: mail body type: plain, html
        :param mail_file: mail attachment files
        """
        self._smtpUser = self._getText(smtp_user)
        self._smtpPass = self._getText(smtp_pass)
        self._mailList = list(filter(None, ''.join(self._getText(mail_dest).split()).split(',')))
        self._smtpHost = self._getText(smtp_host)
        self._smtpPort = self._getText(smtp_port)
        self._smtpStls = smtp_stls
        self._mailSubj = self._getText(mail_subj)
        self._mailText = self._getText(mail_text)
        self._mailType = self._getText(mail_type)
        if mail_from:
            self._mailFrom = self._getText(mail_from)
        else:
            self._mailFrom = self._smtpUser
        if mail_file:
            self._fileList = list(filter(None, ''.join(mail_file.split()).split(',')))
        else:
            self._fileList = None
        self._session = None
        self._mailData = MIMEMultipart()
        self._mailData['From'] = self._mailFrom
        self._mailData['Subject'] = self._mailSubj
        self._mailData.attach(MIMEText(self._mailText, self._mailType))
        if self._fileList:
            for file in self._fileList:
                if path.exists(file):
                    attachment = open(file, "rb")
                    content = MIMEBase('application', 'octet-stream')
                    content.set_payload(attachment.read())
                    encoders.encode_base64(content)
                    content.add_header("Content-Disposition", f"attachment; filename= {path.basename(file)}")
                    self._mailData.attach(content)

    def send(self) -> str:
        """
        Sending the generated email to the destination list
        :return: delivery report string
        """
        report = ''
        try:
            self._session = SMTP(self._smtpHost, int(self._smtpPort))
            if self._smtpStls:
                self._session.starttls()
            self._session.login(self._smtpUser, self._smtpPass)
            for mailTo in self._mailList:
                del self._mailData['To']
                self._mailData['To'] = mailTo
                self._session.sendmail(self._mailFrom, mailTo, self._mailData.as_string())
                report += '"' + self._mailData['Subject'] + '"' + ' send to ' + self._mailData['To'] + '\n'
            self._session.quit()
        except error as err:
            report += "Socket Error: %s" % err
        finally:
            return report

    @classmethod
    def _getText(cls, string: str) -> str:
        """
        If text is a file - read text from this file
        :param string: string of text or file path
        :return: string of input text or file content
        """
        if path.exists(string):
            return open(string).read()
        else:
            return string


def str2bool(value: str) -> bool:
    """
    Converts a string value to boolean
    :param value: string containing "true" or "false", "yes" or "no", "1" or "0"
    :return: bool True or False
    """
    return str(value).lower() in ("true", "yes", "1")


def isConnected(sock_host: str, sock_port: str) -> bool:
    """
    Checking the connection with the host.
    :param sock_host: hostname or ip address
    :param sock_port: port number
    :return: bool True or False
    """
    try:
        sock = create_connection((sock_host, int(sock_port)))
        if sock is not None:
            sock.close
        return True
    except OSError:
        pass
    return False


if __name__ == "__main__":
    from argparse import ArgumentParser

    args = ArgumentParser(
        prog='Mail',
        description='Sending email from Python',
        epilog='Dependencies: Python 3 (tested version 3.9.5)'
    )
    args.add_argument('-u', '--user', type=str, required=True,
                      help='smtp valid user')
    args.add_argument('-p', '--pass', type=str, required=True,
                      help='smtp valid password')
    args.add_argument('-d', '--dest', type=str, required=True,
                      help='destination addresses')
    args.add_argument('--smtp', type=str, default='smtp.gmail.com', required=False,
                      help='smtp hostname or ip address (default: smtp.gmail.com)')
    args.add_argument('--port', type=str, default='587', required=False,
                      help='smtp port number (default: 587)')
    args.add_argument('--stls', type=str2bool, default=True, required=False,
                      help='smtp required tls (default: True)')
    args.add_argument('--from', type=str, default=None, required=False,
                      help='mail from alias (default: <user@smtp>)')
    args.add_argument('--subj', type=str, default='no subject', required=False,
                      help='mail subject (default: "no subject")')
    args.add_argument('--text', type=str, default='no text', required=False,
                      help='mail body text (default: "no text")')
    args.add_argument('--type', type=str, default='plain', required=False,
                      help='mail body type: plain, html (default: plain)')
    args.add_argument('--file', type=str, default=None, required=False,
                      help='mail attachment files (default: None)')
    args.add_argument('--time', type=str, default='3', required=False,
                      help='minutes of attempts to send (default: 3)')
    args = vars(args.parse_args())

    attempts_pass, attempts_wait = 0, 60
    while attempts_pass <= int(args['time']):
        if not isConnected(sock_host=args['smtp'], sock_port=args['port']):
            attempts_pass = attempts_pass + 1
            sleep(attempts_wait)
        else:
            print(Mail(smtp_user=args['user'], smtp_pass=args['pass'], mail_dest=args['dest'],
                       smtp_host=args['smtp'], smtp_port=args['port'], smtp_stls=args['stls'],
                       mail_from=args['from'], mail_subj=args['subj'], mail_text=args['text'],
                       mail_type=args['type'], mail_file=args['file']
                       ).send()
                  )
            break