Attach list of files and email using secure connection

Can I use this function to reliably attach a list of excel files to an email and create a secure connection to transmit said email? My python programming is self taught and I put this function together with a lot of google searches. (This function works, I use it, but I would like to have someone with more experience look it through, if possible)

Where can I improve my code? (Am I using the correct modules?)

import datetime
import smtplib
from email.MIMEMultipart import MIMEMultipart
from email.MIMEText import MIMEText
from email.MIMEBase import MIMEBase
from email import Encoders

sMDY = datetime.date.today().strftime('%m/%d/%y')
lpath = 'C:/Path/to/my/excel/files/'
flist = ['excelfile_1.xlsx', 'excelfile_2.xlsx']

def EMAIL_FILES(flist):
    uname = 'username'
    pword = 'password'

    emailfrom = 'sender@domain.com'
    emailto = [
        'recipient_1@domain.com',
        'recipient_2@domain.com',
        ]

    body = ["The information transmitted is ..."]
    subject = ('Subject with date %s' % sMDY)

    msg = MIMEMultipart()
    msg['From'] = emailfrom
    msg['To'] = ', '.join(emailto)
    msg['Subject'] = subject

    msg.attach(MIMEText(''.join(body)))

    ### ATTACH FILES
    for item in flist:
        part = MIMEBase('application', "octet-stream")

        part.set_payload(open(lpath + item, "rb").read())

        Encoders.encode_base64(part)

        part.add_header('Content-Disposition',
                        'attachment; filename="%s"' % item)
        msg.attach(part)

    ### SECURE CONNECTION
    server = smtplib.SMTP('smtp.domain.com:25')
    server.ehlo()
    server.starttls()
    server.ehlo()
    server.login(uname, pword)

    server.sendmail(emailfrom, emailto, msg.as_string())
    server.quit()

In general, the code looks good. I just have a few miscellaneous remarks.

Code organization

• Function names should be named lower_case_with_underscores by PEP 8.

• I would split the message composition and sending into separate functions.

• It is good practice to avoid embedding passwords into your source code. I suggest storing the account information in a YAML file, or at least as constants in a separate Python module.

-
The parameters are hard-coded, so the function is of limited utility. The function could accept parameters with defaults:

def compose_email(from='sender@example.com',
                  to=['recipient_1@example.com','recipient_2@example.com'],
                  attachments=[])
    …

def send_email(msg, username, password)
    …

Mail content

• The MIME type for .xlsx files is application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.

-
Concatenating file paths using os.path.join(lpath, item) would let you not have to worry about the path component separator. Personally, I would choose to pass full paths to the function instead, to avoid assuming that they are all in some hard-coded directory:

def EMAIL_FILES(attachments):
    …
    for path in attachments:
        with open(path, 'rb') as f:
            part = MIMEBase('application', 'vnd.openxmlformats-officedocument.spreadsheetml.sheet')
            part.set_payload(f.read())
            part.add_header('Content-Disposition',
                'attachment; filename="%s"' % os.path.basename(path))
            Encoders.encode_base64(part)
            msg.attach(part)
    …

EMAIL_FILES([os.path.join('C:/Path/to/my/excel/files/', f) for f in
    ['excelfile_1.xlsx', 'excelfile_2.xlsx']
])

• I'm puzzled by why you defined body as a list of strings, only to join them all into one long string. If the body contains non-trivial content, consider writing it as a """longstring""". Also, you may need to encode the MIMEText using Encoders.encode_quopri().

StackExchange Code Review Q#84218, answer score: 4