email modules and attachments that aren't there

[Russell Bungay]

Hello all,

I have written a short function, based on a recipe in the Python
Cookbook, that sends an e-mail. The function takes arguments that
define who the e-mail is to, from, the subject, the body and an optional
list of attachments.

The function works also perfectly, bar one slight problem. If you
attempt to send an e-mail with just a body and no attachments, the
receiving client still thinks that there is an attachment (so far tested
in Mozilla Thunderbird and the Yahoo! webmail client). Although this
clearly isn't a major problem, it is irritating and I am hoping to use
my code at work. Obviously I can't be sending out badly formed e-mails
to my clients.

I can't for the life of me work out why. I have compared my code to
every example that I can find in the Python documentation, on the
archives of this newsgroup and of the Python Tutor list, and one or two
random searches but can't see what is happening. Any advice or
suggestions would be welcome.

Thank you for your help,

Russell Bungay
--
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Code:

def sendEmail(msg_to, msg_from, msg_subject, message, attachments=[]):

main_msg = email.Message.Message()
main_msg['To'] = ', '.join(msg_to)
main_msg['From'] = msg_from
main_msg['Subject'] = msg_subject
main_msg['Date'] = email.Utils.formatdate(localtime=1)
main_msg['Message-ID'] = email.Utils.make_msgid()
main_msg['Mime-version'] = '1.0'
main_msg['Content-type'] = 'Multipart/mixed'
main_msg.preamble = 'Mime message\n'
main_msg.epilogue = ''

body_encoded = quopri.encodestring(message, 1)
body_msg = email.Message.Message()
body_msg.add_header('Content-type', 'text/plain')
body_msg.add_header('Content-transfer-encoding', 'quoted-printable')
body_msg.set_payload(body_encoded)
main_msg.attach(body_msg)

for attachment in attachments:

content_type, ignored = mimetypes.guess_type(attachment)
if content_type == None:
content_type = 'application/octet-stream'
contents_encoded = cStingIO.StringIO()
attach_file = open(attachment, 'rb')
main_type = content_type[:content_type.find('/')]
if main_type == 'text':
cte = 'quoted-printable'
quopri.encode(attach_file, contents_encoded, 1)
else:
cte = 'base64'
base64.encode(attach_file, contents_encoded)
attach_file.close()

sub_msg = email.Message.Message()
sub_msg.add_header('Content-type', content_type, name=attachment)
sub_msg.add_header('Content-transfer-encoding', cte)
sub_msg.set_payload(contents_encoded.getvalue())
main_msg.attach(sub_msg)

smtp = smtplib.SMTP(server)
smtpfail = smtp.sendmail(msg_from, ', '.join(msg_to),
main_msg.as_string())
smtp.quit()

 

[Gerard Flanagan]

Hello all,

I have written a short function, based on a recipe in the Python
Cookbook, that sends an e-mail. The function takes arguments that
define who the e-mail is to, from, the subject, the body and an optional
list of attachments.

The function works also perfectly, bar one slight problem. If you
attempt to send an e-mail with just a body and no attachments, the
receiving client still thinks that there is an attachment (so far tested
in Mozilla Thunderbird and the Yahoo! webmail client).

Code:

def sendEmail(msg_to, msg_from, msg_subject, message, attachments=[]):

main_msg = email.Message.Message()
main_msg['To'] = ', '.join(msg_to)
main_msg['From'] = msg_from
main_msg['Subject'] = msg_subject
main_msg['Date'] = email.Utils.formatdate(localtime=1)
main_msg['Message-ID'] = email.Utils.make_msgid()
main_msg['Mime-version'] = '1.0'
main_msg['Content-type'] = 'Multipart/mixed'
main_msg.preamble = 'Mime message\n'
main_msg.epilogue = ''

Would it be the 'Content-Type' header? I've no expertise in this, but
doesn't 'multipart' mean 'has attachments'?

Gerard

 

[Russell Bungay]

Hello,

main_msg['Content-type'] = 'Multipart/mixed'

Would it be the 'Content-Type' header? I've no expertise in this, but
doesn't 'multipart' mean 'has attachments'?

Brilliant, thank you. A swift test on the number of attachments and
changing the header suitably does the job.

Thank you for your help,

Russell

 

[Russell Bungay]

Hello,

main_msg['Content-type'] = 'Multipart/mixed'

Would it be the 'Content-Type' header? I've no expertise in this, but
doesn't 'multipart' mean 'has attachments'?

Brilliant, thank you. A swift test on the number of attachments and
changing the header suitably does the job.

That isn't quite all there is to it, the e-mail construction needs a
slight change as well. Roughly working code below.

Ta,

Russell

Code:

def sendEmail(msg_to, msg_from, msg_subject, message, attachments=[]):

main_msg = email.Message.Message()
main_msg['To'] = ', '.join(msg_to)
main_msg['From'] = msg_from
main_msg['Subject'] = msg_subject
main_msg['Date'] = email.Utils.formatdate(localtime=1)
main_msg['Message-ID'] = email.Utils.make_msgid()
main_msg['Mime-version'] = '1.0'
main_msg.preamble = 'Mime message\n'
main_msg.epilogue = ''

body_encoded = quopri.encodestring(message, 1)

if len(attachments) <> 0:
main_msg['Content-type'] = 'Multipart/mixed'
body_msg = email.Message.Message()
body_msg.add_header('Content-type', 'text/plain')
body_msg.add_header('Content-transfer-encoding',
'quoted-printable')
body_msg.set_payload(body_encoded)
main_msg.attach(body_msg)
for attachment in attachments:
content_type, ignored = mimetypes.guess_type(attachment)
if content_type == None:
content_type = 'application/octet-stream'
contents_encoded = cStringIO.StringIO()
attach_file = open(attachment, 'rb')
main_type = content_type[:content_type.find('/')]
if main_type == 'text':
cte = 'quoted-printable'
quopri.encode(attach_file, contents_encoded, 1)
else:
cte = 'base64'
base64.encode(attach_file, contents_encoded)
attach_file.close()

sub_msg = email.Message.Message()
sub_msg.add_header('Content-type', content_type, name=attachment)
sub_msg.add_header('Content-transfer-encoding', cte)
sub_msg.set_payload(contents_encoded.getvalue())
main_msg.attach(sub_msg)

else:
main_msg['Content-type'] = 'text/plain'
main_msg['Content-transfer-encoding'] = 'quoted-printable'
main_msg.set_payload(body_encoded)

smtp = smtplib.SMTP('server')
smtpfail = smtp.sendmail(msg_from, ', '.join(msg_to),
main_msg.as_string())
smtp.quit()

 

[Russell Bungay]

for attachment in attachments:
<snip contents of for loop>

sub_msg = email.Message.Message()
sub_msg.add_header('Content-type', content_type, name=attachment)
sub_msg.add_header('Content-transfer-encoding', cte)
sub_msg.set_payload(contents_encoded.getvalue())
main_msg.attach(sub_msg)

These lines should of course be within the for, not outside it. Apologies.

Russell