email: Examples

Here are a few examples of how to use the email package to read, write, and send simple email messages, as well as more complex MIME messages.

First, let’s see how to create and send a simple text message (both the text content and the addresses may contain unicode characters):

# Import smtplib for the actual sending functionimportsmtplib# Import the email modules we'll needfromemail.messageimportEmailMessage# Open the plain text file whose name is in textfile for reading.withopen(textfile)asfp:# Create a text/plain messagemsg=EmailMessage()msg.set_content(fp.read())# me == the sender's email address# you == the recipient's email addressmsg['Subject']=f'The contents of {textfile}'msg['From']=memsg['To']=you# Send the message via our own SMTP server.s=smtplib.SMTP('localhost')s.send_message(msg)s.quit()

Parsing RFC 822 headers can easily be done by the using the classes from the parser module:

# Import the email modules we'll need#from email.parser import BytesParserfromemail.parserimportParserfromemail.policyimportdefault# If the e-mail headers are in a file, uncomment these two lines:# with open(messagefile, 'rb') as fp:# headers = BytesParser(policy=default).parse(fp)# Or for parsing headers in a string (this is an uncommon operation), use:headers=Parser(policy=default).parsestr('From: Foo Bar <user@example.com>\n''To: <someone_else@example.com>\n''Subject: Test message\n''\n''Body would go here\n')# Now the header items can be accessed as a dictionary:print('To: {}'.format(headers['to']))print('From: {}'.format(headers['from']))print('Subject: {}'.format(headers['subject']))# You can also access the parts of the addresses:print('Recipient username: {}'.format(headers['to'].addresses[0].username))print('Sender name: {}'.format(headers['from'].addresses[0].display_name))

Here’s an example of how to send a MIME message containing a bunch of family pictures that may be residing in a directory:

# Import smtplib for the actual sending function.importsmtplib# Here are the email package modules we'll need.fromemail.messageimportEmailMessage# Create the container email message.msg=EmailMessage()msg['Subject']='Our family reunion'# me == the sender's email address# family = the list of all recipients' email addressesmsg['From']=memsg['To']=', '.join(family)msg.preamble='You will not see this in a MIME-aware mail reader.\n'# Open the files in binary mode. You can also omit the subtype# if you want MIMEImage to guess it.forfileinpngfiles:withopen(file,'rb')asfp:img_data=fp.read()msg.add_attachment(img_data,maintype='image',subtype='png')# Send the email via our own SMTP server.withsmtplib.SMTP('localhost')ass:s.send_message(msg)

Here’s an example of how to send the entire contents of a directory as an email message: [1]

#!/usr/bin/env python3"""Send the contents of a directory as a MIME message."""importosimportsmtplib# For guessing MIME type based on file name extensionimportmimetypesfromargparseimportArgumentParserfromemail.messageimportEmailMessagefromemail.policyimportSMTPdefmain():parser=ArgumentParser(description="""\Send the contents of a directory as a MIME message.Unless the -o option is given, the email is sent by forwarding to your localSMTP server, which then does the normal delivery process. Your local machinemust be running an SMTP server.""")parser.add_argument('-d','--directory',help="""Mail the contents of the specified directory, otherwise use the current directory. Only the regular files in the directory are sent, and we don't recurse to subdirectories.""")parser.add_argument('-o','--output',metavar='FILE',help="""Print the composed message to FILE instead of sending the message to the SMTP server.""")parser.add_argument('-s','--sender',required=True,help='The value of the From: header (required)')parser.add_argument('-r','--recipient',required=True,action='append',metavar='RECIPIENT',default=[],dest='recipients',help='A To: header value (at least one required)')args=parser.parse_args()directory=args.directoryifnotdirectory:directory='.'# Create the messagemsg=EmailMessage()msg['Subject']=f'Contents of directory {os.path.abspath(directory)}'msg['To']=', '.join(args.recipients)msg['From']=args.sendermsg.preamble='You will not see this in a MIME-aware mail reader.\n'forfilenameinos.listdir(directory):path=os.path.join(directory,filename)ifnotos.path.isfile(path):continue# Guess the content type based on the file's extension. Encoding# will be ignored, although we should check for simple things like# gzip'd or compressed files.ctype,encoding=mimetypes.guess_file_type(path)ifctypeisNoneorencodingisnotNone:# No guess could be made, or the file is encoded (compressed), so# use a generic bag-of-bits type.ctype='application/octet-stream'maintype,subtype=ctype.split('/',1)withopen(path,'rb')asfp:msg.add_attachment(fp.read(),maintype=maintype,subtype=subtype,filename=filename)# Now send or store the messageifargs.output:withopen(args.output,'wb')asfp:fp.write(msg.as_bytes(policy=SMTP))else:withsmtplib.SMTP('localhost')ass:s.send_message(msg)if__name__=='__main__':main()

Here’s an example of how to unpack a MIME message like the one above, into a directory of files:

#!/usr/bin/env python3"""Unpack a MIME message into a directory of files."""importosimportemailimportmimetypesfromemail.policyimportdefaultfromargparseimportArgumentParserdefmain():parser=ArgumentParser(description="""\Unpack a MIME message into a directory of files.""")parser.add_argument('-d','--directory',required=True,help="""Unpack the MIME message into the named directory, which will be created if it doesn't already exist.""")parser.add_argument('msgfile')args=parser.parse_args()withopen(args.msgfile,'rb')asfp:msg=email.message_from_binary_file(fp,policy=default)try:os.mkdir(args.directory)exceptFileExistsError:passcounter=1forpartinmsg.walk():# multipart/* are just containersifpart.get_content_maintype()=='multipart':continue# Applications should really sanitize the given filename so that an# email message can't be used to overwrite important filesfilename=part.get_filename()ifnotfilename:ext=mimetypes.guess_extension(part.get_content_type())ifnotext:# Use a generic bag-of-bits extensionext='.bin'filename=f'part-{counter:03d}{ext}'counter+=1withopen(os.path.join(args.directory,filename),'wb')asfp:fp.write(part.get_payload(decode=True))if__name__=='__main__':main()

Here’s an example of how to create an HTML message with an alternative plain text version. To make things a bit more interesting, we include a related image in the html part, and we save a copy of what we are going to send to disk, as well as sending it.

#!/usr/bin/env python3importsmtplibfromemail.messageimportEmailMessagefromemail.headerregistryimportAddressfromemail.utilsimportmake_msgid# Create the base text message.msg=EmailMessage()msg['Subject']="Pourquoi pas des asperges pour ce midi ?"msg['From']=Address("Pepé Le Pew","pepe","example.com")msg['To']=(Address("Penelope Pussycat","penelope","example.com"),Address("Fabrette Pussycat","fabrette","example.com"))msg.set_content("""\Salut!Cette recette [1] sera sûrement un très bon repas.[1] http://www.yummly.com/recipe/Roasted-Asparagus-Epicurious-203718--Pepé""")# Add the html version. This converts the message into a multipart/alternative# container, with the original text message as the first part and the new html# message as the second part.asparagus_cid=make_msgid()msg.add_alternative("""\<html> <head></head> <body> <p>Salut!</p> <p>Cette <a href="http://www.yummly.com/recipe/Roasted-Asparagus-Epicurious-203718"> recette </a> sera sûrement un très bon repas. </p> <img src="cid:{asparagus_cid}"> </body></html>""".format(asparagus_cid=asparagus_cid[1:-1]),subtype='html')# note that we needed to peel the <> off the msgid for use in the html.# Now add the related image to the html part.withopen("roasted-asparagus.jpg",'rb')asimg:msg.get_payload()[1].add_related(img.read(),'image','jpeg',cid=asparagus_cid)# Make a local copy of what we are going to send.withopen('outgoing.msg','wb')asf:f.write(bytes(msg))# Send the message via local SMTP server.withsmtplib.SMTP('localhost')ass:s.send_message(msg)

If we were sent the message from the last example, here is one way we could process it:

importosimportsysimporttempfileimportmimetypesimportwebbrowser# Import the email modules we'll needfromemailimportpolicyfromemail.parserimportBytesParserdefmagic_html_parser(html_text,partfiles):"""Return safety-sanitized html linked to partfiles. Rewrite the href="cid:...." attributes to point to the filenames in partfiles. Though not trivial, this should be possible using html.parser. """raiseNotImplementedError("Add the magic needed")# In a real program you'd get the filename from the arguments.withopen('outgoing.msg','rb')asfp:msg=BytesParser(policy=policy.default).parse(fp)# Now the header items can be accessed as a dictionary, and any non-ASCII will# be converted to unicode:print('To:',msg['to'])print('From:',msg['from'])print('Subject:',msg['subject'])# If we want to print a preview of the message content, we can extract whatever# the least formatted payload is and print the first three lines. Of course,# if the message has no plain text part printing the first three lines of html# is probably useless, but this is just a conceptual example.simplest=msg.get_body(preferencelist=('plain','html'))print()print(''.join(simplest.get_content().splitlines(keepends=True)[:3]))ans=input("View full message?")ifans.lower()[0]=='n':sys.exit()# We can extract the richest alternative in order to display it:richest=msg.get_body()partfiles={}ifrichest['content-type'].maintype=='text':ifrichest['content-type'].subtype=='plain':forlineinrichest.get_content().splitlines():print(line)sys.exit()elifrichest['content-type'].subtype=='html':body=richestelse:print("Don't know how to display {}".format(richest.get_content_type()))sys.exit()elifrichest['content-type'].content_type=='multipart/related':body=richest.get_body(preferencelist=('html'))forpartinrichest.iter_attachments():fn=part.get_filename()iffn:extension=os.path.splitext(part.get_filename())[1]else:extension=mimetypes.guess_extension(part.get_content_type())withtempfile.NamedTemporaryFile(suffix=extension,delete=False)asf:f.write(part.get_content())# again strip the <> to go from email form of cid to html form.partfiles[part['content-id'][1:-1]]=f.nameelse:print("Don't know how to display {}".format(richest.get_content_type()))sys.exit()withtempfile.NamedTemporaryFile(mode='w',delete=False)asf:f.write(magic_html_parser(body.get_content(),partfiles))webbrowser.open(f.name)os.remove(f.name)forfninpartfiles.values():os.remove(fn)# Of course, there are lots of email messages that could break this simple# minded program, but it will handle the most common ones.

Up to the prompt, the output from the above is:

To: Penelope Pussycat <penelope@example.com>, Fabrette Pussycat <fabrette@example.com> From: Pepé Le Pew <pepe@example.com> Subject: Pourquoi pas des asperges pour ce midi ? Salut! Cette recette [1] sera sûrement un très bon repas. 

Footnotes

[1]

Thanks to Matthew Dixon Cowles for the original inspiration and examples.