Email with no attachment is showing paperclip

Question

I am using Python to send a simple HTML email and have the basic code:

import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
from email.mime.application import MIMEApplication

def send_test_mail(body):
    sender_email = <SenderEmail>
    receiver_email = <ReceiverEmail>

    msg = MIMEMultipart()
    msg['Subject'] = '[Email Test]'
    msg['From'] = sender_email
    msg['To'] = receiver_email
    
    msgText = MIMEText('<b>%s</b>' % (body), 'html')
    msg.attach(msgText)

    try:
        with smtplib.SMTP_SSL('smtp.gmail.com', 587) as smtpObj:
            smtpObj.ehlo()
            smtpObj.login(<LoginUserName>, <LoginPassword>)
            smtpObj.sendmail(sender_email, receiver_email, msg.as_string())
    except Exception as e:
        print(e)
       
if __name__ == "__main__":
    send_test_mail("Welcome to Medium!")

This has been put together from a couple of sources from within the stackexchange community but the intention is only to send a straightforward email.

But, when it is received, I get the paperclip icon indicating there is an attachment when there clearly isn't one. https://i.stack.imgur.com/Ysj3g.png

Python is not my strong point but I'm sure it has more to do with SMTPLIB rather than python.

Does anyone know what is going on here?

Thanks