SMTP Email script doesn't work on Mac but works on Windows

Question

I have some code used to send emails. It works on windows but when I try run it on a mac (with the same user login as on the windows machine), it doesn't send an email or return any errors.

Anyone have any experience with this kinda thing, or examples, tips, solutions pls?

import smtplib
import mimetypes
from email import encoders
from email.message import Message
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText


import platform

SERVER = "mail.myCompany.co.za"
COMMASPACE = ', '


SUBJECT = "testing"
TEXT = "mac dev test\n\nSent from: " + platform.platform()
TO = [ 'jared.glass@myCompany.co.za' ]
FROM = "jared.glass@myCompany.co.za"


# connect to the server
smtp = smtplib.SMTP( SERVER )

smtp.ehlo()


# if attachments are too big, try gain and just add them as links
# Create the container (outer) email message.
msg = MIMEMultipart()
msg['Subject'] = SUBJECT
msg['From'] = FROM
msg['To'] = COMMASPACE.join(TO)      
msg.attach( MIMEText( TEXT , 'plain') )

smtp.sendmail( FROM , TO , msg.as_string() )


smtp.close()               
print(" ---- SUCCESS ---- mail sent ---- ")