Permission Denied error while sending mail using Python smtplib
#from email import Encoders
from email.mime.base import MIMEBase
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.utils import COMMASPACE, formatdate
import os
import smtplib
from base64 import encode
from email import encoders

def sendMail(to, subject, text, files=[],server="smtp.mydomain.com"):
    assert type(to)==list
    assert type(files)==list
    fro = "From <myemail@mydomain.com>"

    msg = MIMEMultipart()
    msg['From'] = fro
    msg['To'] = COMMASPACE.join(to)
    msg['Date'] = formatdate(localtime=True)
    msg['Subject'] = subject

    msg.attach( MIMEText(text) )

    for file in files:
        part = MIMEBase('application', "octet-stream")
        part.set_payload( open(file,"rb").read() )
        encoders.encode_base64(part)
        part.add_header('Content-Disposition', 'attachment; filename="%s"'
                       % os.path.basename(file))
        msg.attach(part)

    smtp = smtplib.SMTP_SSL(server, 465)
    smtp.ehlo()
    smtp.set_debuglevel(1)
    smtp.ehlo()
    smtp.login("myemail@mydomain.com", "mypassword")
    smtp.ehlo()
    smtp.sendmail(fro, to, msg.as_string() )
    smtp.close()
    print("Email send successfully.")

sendMail(
        ["recipient"],
        "hello","cheers",
        []
    )

raise SMTPSenderRefused(code, resp, from_addr)
smtplib.SMTPSenderRefused: (501, b'5.7.1 <myemail@mydomain.com>... Permission denied', 'myemail@mydomain.com')