用jinja做了个E-Letter小项目

做了一个html E-Letter项目.
邮件模板采用jinja2, html 邮件内容生成简直太爽了.
整个项目开发只用了2个小时, 调试却花了大半天时间, 生成的邮件总是发不出去.

于是, 打开 smtp 的debuglevel, 发现邮件已经mail queue了, 但就是收不到邮件. mail server是exchange. 之前用java写过类似的程序也没有问题(也是走smtp协议发送html邮件). 为什么这次用python实现却有问题?

怀疑过python smtp模块用法, 怀疑过python smtp的html写法, 怀疑过smtp subject和content不支持unicode. 最终都被排除.
最后终于定位到元凶: 邮件的subject只要包含"Please check."这13个字符, 邮件就会石沉大海. 难道是exchange server设了某种规则?

#------------------
资料:
#------------------
cnblogs 小五义的文章不错,  <<python发送各类邮件的主要方法>>,
 http://www.cnblogs.com/xiaowuyi/archive/2012/03/17/2404015.html

#------------------
代码结构
#------------------
下面简单描述一下项目的结构, 在我的脚手架项目基础上, 做了少量的裁剪, 并增加两个目录, scripts和templates, scripts目录存放E-Letter生成和发送脚本, templates目录存放E-Letter的模板.
并附上 mail_service.py, 修改了网上找的代码, 用来发送 html 邮件.  

 
py_package
      |--scripts
               |--check1.py
               |--check2.py
      |--templates
               |--check1.html
               |--check2.html
              

# -*- coding: utf-8 -*-
#check1.py 
'''
Created on 2014-5-23

''' 
          
from __future__ import absolute_import          
import jinja2 
from jinja2.loaders import FileSystemLoader
      
def get_template(file_name):
    '''
    get template html with jinja2 format in templates folder
    '''
    template_path=os.path.join(os.path.dirname(os.path.dirname(__file__)),'templates')
    template_env = jinja2.Environment(loader=FileSystemLoader(template_path))       
    return template_env.get_template(file_name)

    
def check():
    template=get_template('check1.html')
    something='something here'
    mail_body=template.render(something=something)
    mail_sender=HtmlMailSender() 
    mail_subject='Some subject here'
    #mail_subject='Please check.'  #cannot send out, why? 
    mail_to=['a@corp.com','b.corp.com']
    mail_cc=[] 
    mail_sender.send_html_mail(mail_to,mail_cc,mail_subject,mail_body)    

      

    
# -*- coding: utf-8 -*-
#conf.py 
'''
Created on 2014-6-23

'''
from __future__ import absolute_import
import logging

##logging
log_level=logging.INFO 

 
#email setting 
smtp_host="10.10.10.10" 
smtp_port=25 
smtp_over_ssl=False
mail_user="a@corp.com" 
mail_pwd=""    # if no auth required, set pwd as empty
 

   

# -*- coding: utf-8 -*-
#mail_service.py 
'''
Created on 2014-6-23

'''
from __future__ import absolute_import
import logging
from . import conf


class HtmlMailSender(object):
    logger=logging.getLogger(__name__)
    
    def __init__(self):
        #read mail settings from configure file
        self.smtp_host=conf.smtp_host
        self.smtp_port=conf.smtp_port
        self.smtp_over_ssl=conf.smtp_over_ssl
        self.mail_user=conf.mail_user
        self.mail_pwd=conf.mail_pwd        
        
        
            
    def send_html_mail(self, to_list, cc_list, subject, body):
        self.logger.info('send_html_mail() called.')
     
        import smtplib
        from email.mime.text import MIMEText  
        from email.mime.multipart import MIMEMultipart  

        # Construct email
        msgRoot = MIMEMultipart('related')
        msgRoot['Subject'] = subject    
        msgRoot['From'] = self.mail_user  
        msgRoot['To'] = ",".join(to_list)  
        msgRoot['CC'] =",".join(cc_list)   
        #msgRoot['BCC'] =",".join(cc_list)
        msgRoot.preamble = 'This is a multi-part message in MIME format.'
   
        # Encapsulate the plain and HTML versions of the message body in an
        # 'alternative' part, so message agents can decide which they want to display.
        msgAlternative = MIMEMultipart('alternative')
        msgRoot.attach(msgAlternative)
        
        #Add plain content
        msgText = MIMEText('This is HTML mail. If you see this message, which means you will not see the real mail content.','plain')
        msgAlternative.attach(msgText)
        
        #add html content
        msgText = MIMEText(body, 'html')
        msgAlternative.attach(msgText)
 
        try:
            if not self.smtp_over_ssl:
                if self.smtp_port=='':
                    s = smtplib.SMTP(self.smtp_host)
                else:
                    s = smtplib.SMTP(self.smtp_host, self.smtp_port)
            else:
                if self.smtp_port=='':
                    s = smtplib.SMTP_SSL(self.smtp_host)
                else:
                    s = smtplib.SMTP_SSL(self.smtp_host, self.smtp_port)
                    
            s.set_debuglevel(True)  # print stmp actions to stdout
            if self.mail_pwd :
                s.login(self.mail_user,self.mail_pwd)  
    
            to_addrs=to_list+cc_list
            s.sendmail(self.mail_user ,to_addrs, msgRoot.as_string())  
            #s.sendmail(from_addr ,to_addrs, 'test message')
            s.quit()    
            
            self.logger.info("""Mail sent. Find details below, 
            to_list: %s 
            cc_list: %s 
            subject: %s 
            body: %s"""%(to_list, cc_list, subject, body))                     
            return True  
        except Exception, ex:  
            self.logger.exception(ex)  
            return False