Monitoring number of smtp bytes sent through python e-mail socket

[William Connery]

Hi,

I have a small python program with e-mail capabilities that I have pieced together from code snippets found on the internet.

The program uses the smtplib module to successfully send an e-mail with an attachment.

I want to give users an indication of the percentage of the e-mail that has already been sent so as to avoid frustration when dealing with large attachments or a slow smtp server. But the smtplib module doesn't seem to provide access to the number of bytes that have already been sent.

Can anyone help, or provide a working example of sending an e-mail attachment using basic python sockets whilst having access to the number of bytes that have already been sent through the socket?

Many thanks.

William Connery

#!/usr/bin/python
 
import wx
import smtplib
from email import Encoders
from email.MIMEMultipart import MIMEMultipart
from email.Utils import COMMASPACE, formatdate
from email.MIMEBase import MIMEBase
from email.MIMEText import MIMEText
import os
 
# set a few variables to make testing less tedious
 
# you need to set your smtp server domain name
smtp_server = 'smtp.your_isp_domain.com'
 
toemail = '[e-mail]'
fromemail = '[e-mail]'
subject = 'Testing python smtplib module'
emailmsg = 'How do I determine the number of bytes that have been ' +\
'forwarded whilst the e-mail is being sent?\n\nSending large (or many) ' +\
'attachments may take some time, and I\'d like to use a gauge ' +\
'control to give users an indication of the percentage of ' +\
'the e-mail that has already been sent.\n\nThe smtplib module relies ' +\
'on sockets, but I don\'t know how to use python sockets to ' +\
'send an e-mail with attachments and concurrently monitor the ' +\
'number of bytes that have already been sent.\n\nHelp !'
 
# attachment file
attachment = 'C:\\Documents and Settings\\-\\Desktop\\test.zip'
#attachment = '/home/user1/Desktop/test.zip'
 
 
# variable to hold bytes that have been sent
bytes_sent = 0
 
 
 
 
class MainFrame(wx.Frame):
    def __init__(self, *args, **kwargs):
        wx.Frame.__init__(self, *args, **kwargs)
        self.SetSize(wx.Size(750,550))
        self.SetTitle('Monitoring the number of bytes sent during ' +\
        'a python e-mail send  -  How ?')
 
        panel = wx.Panel(self)
 
        vertsizer = wx.BoxSizer(wx.VERTICAL)
 
        flexsizer = wx.FlexGridSizer(rows=8, cols=2, hgap=10, vgap=10)
        flexsizer.AddGrowableCol(1)
        flexsizer.AddGrowableRow(4)
 
        tolabel = wx.StaticText(panel, -1, "To E-mail Address:")
        flexsizer.Add(tolabel,0,wx.ALIGN_RIGHT|wx.ALIGN_CENTER_VERTICAL)
        self.toemailaddress = wx.TextCtrl(panel)
        flexsizer.Add(self.toemailaddress,0,wx.EXPAND)
 
        fromlabel = wx.StaticText(panel, -1, "From E-mail Address:")
        flexsizer.Add(fromlabel,0,wx.ALIGN_RIGHT|wx.ALIGN_CENTER_VERTICAL)
        self.fromemailaddress = wx.TextCtrl(panel)
        flexsizer.Add(self.fromemailaddress,0,wx.EXPAND)
 
        attachmentbutton = wx.Button(panel, 1001, "File Attachment")
        attachmentbutton.Bind(wx.EVT_BUTTON, self.SelectAttachmentFile)
        flexsizer.Add(attachmentbutton,0,wx.ALIGN_RIGHT|wx.ALIGN_CENTER_VERTICAL)
        self.attachmenteditbox = wx.TextCtrl(panel, style = wx.TE_CENTRE)
        self.attachmenteditbox.Disable()
        flexsizer.Add(self.attachmenteditbox,0,wx.EXPAND)
 
        subjectlabel = wx.StaticText(panel, -1, "Subject:")
        flexsizer.Add(subjectlabel,0,wx.ALIGN_RIGHT|wx.ALIGN_CENTER_VERTICAL)
        self.subject = wx.TextCtrl(panel)
        flexsizer.Add(self.subject,0,wx.EXPAND)
 
        messagelabel = wx.StaticText(panel, -1, "E-mail Message:")
        flexsizer.Add(messagelabel,0,wx.ALIGN_RIGHT)
        self.emailmessage = wx.TextCtrl(panel, style = wx.TE_MULTILINE)
        flexsizer.Add(self.emailmessage,1,wx.EXPAND)
 
        flexsizer.AddSpacer(wx.Size(1,1))
 
        self.gauge = wx.Gauge(panel)
        self.gauge.SetRange(100)
        self.gauge.SetValue(30)
        sendbutton = wx.Button(panel, 1001, "Send E-mail")
        sendbutton.Bind(wx.EVT_BUTTON, self.SendTheEmail)
        hsizer = wx.BoxSizer(wx.HORIZONTAL)
        hsizer.Add(self.gauge,1,wx.RIGHT,15)
        hsizer.Add(sendbutton,0,wx.ALIGN_CENTER_VERTICAL)
        flexsizer.Add(hsizer,0,wx.EXPAND)
 
        byteslabel1 = wx.StaticText(panel, -1, "Bytes to Send:")
        self.bytestosend = wx.StaticText(panel, -1, "0")
        flexsizer.Add(byteslabel1,0,wx.ALIGN_RIGHT)
        flexsizer.Add(self.bytestosend,0,wx.EXPAND)
 
        byteslabel2 = wx.StaticText(panel, -1, "Bytes Sent:")
        self.bytessent = wx.StaticText(panel, -1, "0")
        flexsizer.Add(byteslabel2,0,wx.ALIGN_RIGHT)
        flexsizer.Add(self.bytessent,0,wx.EXPAND)
 
 
        vertsizer.Add(flexsizer,1, wx.EXPAND|wx.ALL,30)
 
        # place values into appropriate text fields
        # (these values can be initialized at the top of this script)
 
        self.toemailaddress.SetValue(toemail)
        self.fromemailaddress.SetValue(fromemail)
        self.subject.SetValue(subject)
        self.emailmessage.SetValue(emailmsg)
 
        if os.path.exists(os.path.abspath(attachment)):
            self.attachmenteditbox.SetValue(\
            os.path.split(os.path.abspath(attachment))[1])
 
        panel.SetSizer(vertsizer)
 
        self.bytestosend.SetLabel(str(self.GetMimeSize()))
 
 
 
    # select an attachment file for the e-mail
    def SelectAttachmentFile(self, event):
 
        filedlgbox = wx.FileDialog(self,\
            message="Select  an Attachment  File", \
            defaultDir=os.getcwd(), \
            defaultFile='', \
            wildcard="Any File (*.*)|*.*", \
            style=wx.OPEN | wx.CHANGE_DIR | wx.HIDE_READONLY)
 
        if filedlgbox.ShowModal() == wx.ID_OK:
            global attachment
            attachment = filedlgbox.GetFilenames()[0].strip()
            self.attachmenteditbox.SetValue(os.path.split(attachment)[1])
 
        filedlgbox.Destroy()
 
        self.bytestosend.SetLabel(str(self.GetMimeSize()))
 
        event.Skip()
 
 
 
    def GetMimeSize(self):
 
        # get size of current e-mail mime object
 
        tempmime = MIMEMultipart()
        tempmime['To'] = self.toemailaddress.GetValue().strip()
        tempmime['From'] = self.fromemailaddress.GetValue().strip()
        tempmime['Subject'] = self.subject.GetValue().strip()
 
        # add the e-mail message to the mime object
        tempmime.attach(MIMEText(self.emailmessage.GetValue()))
 
        # add an attachment file to the mime object if selected
        if attachment.strip() != '':
            thisfile = os.path.abspath(attachment)
            if os.path.exists(thisfile):
                attachmentmime = MIMEBase('application', "octet-stream")
                attachmentmime.set_payload( open(thisfile,"rb").read())
                Encoders.encode_base64(attachmentmime)
                attachmentmime.add_header('Content-Disposition',\
                'attachment; filename="%s"' % os.path.basename(thisfile))
                tempmime.attach(attachmentmime)
 
        mimesize = len(tempmime.as_string())
 
        tempmime = None
 
        return mimesize
 
 
    # send the e-mail using python's smtplib module
    def SendTheEmail(self, event):
 
        # how can I determine the number of bytes that have
        # been forwarded whilst the e-mail is being sent ?
        global bytes_sent
        bytes_sent = 0
 
        # set gauge value to zero - max value = 100 (%)
        self.gauge.SetValue(0)
 
        self.bytestosend.SetLabel(str(self.GetMimeSize()))
        self.bytessent.SetLabel('0')
 
        # create a multi-part mime object for the
        # e-mail message and file attachment
 
        thismime = MIMEMultipart()
        thismime['To'] = self.toemailaddress.GetValue().strip()
        thismime['From'] = self.fromemailaddress.GetValue().strip()
        thismime['Subject'] = self.subject.GetValue().strip()
 
        # add the e-mail message to the mime object
        thismime.attach(MIMEText(self.emailmessage.GetValue()))
 
        # add an attachment file to the mime object if selected
        if attachment.strip() != '':
            thisfile = os.path.abspath(attachment)
            if os.path.exists(thisfile):
                attachmentmime = MIMEBase('application', "octet-stream")
                attachmentmime.set_payload( open(thisfile,"rb").read())
                Encoders.encode_base64(attachmentmime)
                attachmentmime.add_header('Content-Disposition',\
                'attachment; filename="%s"' % os.path.basename(thisfile))
                thismime.attach(attachmentmime)
            else:
                dlg = wx.MessageDialog(self,\
                message='Attachment file ' + thisfile + ' is missing.',\
                caption='Attachment Missing',style=wx.OK|\
                wx.ICON_INFORMATION)
                dlg.ShowModal()
                dlg.Destroy()
 
        # send the e-mail
        smtpobj = smtplib.SMTP(smtp_server)
        smtpobj.sendmail(self.fromemailaddress.GetValue().strip(), \
                            self.toemailaddress.GetValue().strip(), \
                            thismime.as_string())
 
        smtpobj.close()
 
 
        event.Skip()
 
 
 
if __name__ == '__main__':
    app = wx.App()
    theframe = MainFrame(None)
    theframe.Show()
    app.MainLoop()
 
 
 

[bartonc]

I'm looking into socket byte counts. In the meantime, one line stuck out as I was reading your code:

        tempmime = None
 

doesn't free up memory immediately. It does set the refcount to zero (if there are no other reference) by reseting the value of the temporary variable to None, so it will eventually be garbage collected. Your intention was probably to

        del tempmime
 

which frees up memory immediately.