send email

一直觉得发送邮件再简单不过，直到最近深陷几个邮件大坑，费了不少时间才爬出来，当然其中也不乏公司环境给我挖的坑，代码不断，填坑不止呀……

python发邮件主要是借助框架( 如Django)，以及pure python，其实底层都一样。

借助Django，具体settings及发送邮件code如下：

EMAIL_HOST_USER = '*****'
DEFAULT_FROM_EMAIL = EMAIL_HOST_USER
EMAIL_FROM = EMAIL_HOST_USER
EMAIL_HOST = 'smtp.partner.outlook.cn'
EMAIL_HOST_PASSWORD = 'Pul13448'
＃看邮箱配置
EMAIL_PORT = 587
＃看邮箱配置
EMAIL_USE_TLS = True
EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'

from django.core.mail import EmailMessage
import os
def send_mail_attachment(subject,body,to=[],attach_file=None):
    try:
        email = EmailMessage(subject,body,from_email=DEFAULT_FROM_EMAIL,to=to)
        attach_file =  os.path.join(BASE_DIR,attach_file)
        email.attach_file(attach_file)
        email.send(fail_silently=False)
        print('send mail success,mail attachment:{}'.format(attach_file))
        return True
    except Exception as e:
        logger.exception(e)
        return False

pure python,这里介绍通过thread发送，如下：

class EmailThreadPure(threading.Thread):
    def __init__(self, subject, message, fail_silently=False, html_message=None):
        self.smtpserver = EMAIL_HOST
        self.user = EMAIL_HOST_USER
        self.sender = EMAIL_HOST_USER
        self.receiver = [a[1] for a in settings.ADMINS]
        self.body = message
        self.subject = subject
        self.html_message = html_message
        threading.Thread.__init__(self)
    
    def attach(self):
      """if attachment,use it"""
        ctype, encoding = mimetypes.guess_type(self.attach_file)
        if ctype is None or encoding is not None:
            ctype = "application/octet-stream"
        maintype, subtype = ctype.split("/", 1)
        if maintype == "text":
            with open(self.attach_file, "rb") as fp:
                # Note: we should handle calculating the charset
                attachment = MIMEText(fp.read(), _subtype=subtype)
        elif maintype == "image":
            with open(self.attach_file, "rb") as fp:
                attachment = MIMEImage(fp.read(), _subtype=subtype)
        elif maintype == "audio":
            with open(self.attach_file, "rb") as fp:
                attachment = MIMEAudio(fp.read(), _subtype=subtype)
        else:
            with open(self.attach_file, "rb") as fp:
                attachment = MIMEBase(maintype, subtype)
                attachment.set_payload(fp.read())
            encoders.encode_base64(attachment)
        encoders.encode_base64(attachment)
        attachment.add_header("Content-Disposition", "attachment", filename=self.attach_file)
        self.msg.attach(attachment)

    def run(self):
        # use html and plain mode,if no html,just self.msg = MIMEMultipart()
        self.msg = MIMEMultipart('alternative')
        self.msg['Subject'] = Header('%s%s' % (settings.EMAIL_SUBJECT_PREFIX, self.subject), 'utf-8')
        self.msg['from'] = EMAIL_HOST_USER
        # msg[to] is a string
        self.msg['to'] = ', '.join(self.receiver)
        self.msg.attach(MIMEText(self.body, 'plain', 'utf-8'))
        self.msg.attach(MIMEText(self.html_message, 'html', 'utf-8'))
        server = smtplib.SMTP(self.smtpserver, EMAIL_PORT, timeout=30)
        #debug mode
        # server.set_debuglevel(1)
        
        # USE TLS
        server.ehlo()
        server.starttls()
        
        # if need login
        server.login(EMAIL_HOST_USER,EMAIL_HOST_PASSWORD)
        #self.receiver is a list
        server.sendmail(self.sender, self.receiver, self.msg.as_string())
        server.quit()

列坑

DEFAULT_FROM_EMAIL与send mail中的from_email不一致。

error info：

SMTPDataError: (554, ‘5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message.

fix：统一DEFAULT_FROM_EMAIL与send mail中的from_email

应该使用tsl时，未设置tsl。

error info：AUTH extension not supported by server

fix：设置tsl，settings设置或者

mail.ehlo() 
mail.starttls()

python pure发邮件时，当多个收件人，可能只有第一个收件人能收到。

error info:无，但会发现只有第一个人收到。

fix：因为self.receiver为str的时候，会自动截取第一个。

self.msg[‘to’] = ‘, ‘.join(self.receiver)

server.sendmail(self.sender, self.receiver, self.msg.as_string())

self.receiver为list
如果settings配置错误，很有可能是不会报错并且返回发送邮件数量也为1，但实际上是收不到邮件，检查端口号及tsl和ssl 配置。我碰到的情况时logger中设置的mail setting与Django setting backend不一样，加上公司邮箱设置问题，导致mail setting 里的邮件发不出来。
未设置timeout时间，导致一直在connect mail server，无log，会误认为已经发送好了。 error info: 无，退出时会出现connect timeout，否则会一直连接。 fix：设置timeout时间。可以使用telnet server port方式看是否连接有问题。
避开敏感词汇，否则也可能会报554错误，如test等。

列坑

CATALOG

FEATURED TAGS

FRIENDS