Python server.sendmail() 返回 {}。电子邮件未发送

Question

我有一个包含很多行的 file.txt 文件。我希望随机选择任何一行并通过电子邮件发送。这是循环三次。

import smtplib,datetime,random

def mail(em):
    #print "yo"
    fromAddress = "atadmorecouth@gmail.com"
    toAddress = "atadmorecouth@gmail.com"
    subject = "WOW " + str(datetime.datetime.now())
    #print subject
    msg = em
    server=smtplib.SMTP("smtp.gmail.com", 587)
    server.starttls()
    password = "mypassword"
    server.login(fromAddress, password)
    server.sendmail(fromAddress, toAddress, msg)
    #print server.sendmail(fromAddress, toAddress, msg)


for i in range(0,3):
    em=str(random.choice(list(open('file.txt'))))
    mail(em)

此代码无效。登录和一切都很好。我注意到的唯一问题是 server.sendmail(fromAddress, toAddress, msg) 返回一个空的 {}可能的解决方法是什么？首先是什么问题？我在终端中运行了 mail() 函数，它似乎工作正常。所有文件都托管 here

Answer 1

首先，作为the docs说:

If this method does not raise an exception, it returns a dictionary, with one entry for each recipient that was refused.

因此，您返回 {} 不是问题；这意味着您没有错误。

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其次，您发送的不是有效消息。消息必须包含标题，然后是空行，然后是正文。 header 应至少包含 From: 和 To:。

smtplib 库不会为您做这些；如 the example 中所述:

Note that the headers to be included with the message must be included in the message as entered; this example doesn’t do any processing of the RFC 822 headers. In particular, the ‘To’ and ‘From’ addresses must be included in the message headers explicitly.

...

Note: In general, you will want to use the email package’s features to construct an email message, which you can then convert to a string and send via sendmail(); see email: Examples.

或者，在 sendmail文档:

Note: The from_addr and to_addrs parameters are used to construct the message envelope used by the transport agents. The SMTP does not modify the message headers in any way.

在这种情况下(如示例中所示)，只需手动制作消息就足够简单了:

msg = "From: {}\r\nTo: {}\r\n\r\n{}\r\n".format(fromAddress, toAddress, em)

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最后，你真的应该调用 server.quit()在 mail 函数的末尾。虽然(至少在 CPython 中)server 对象将在函数结束后立即销毁，但与 Python 中的许多其他对象不同，SMTP 对象不会调用 close 销毁时，更不用说 quit 了。所以，从服务器的角度来看，你突然断开了连接。虽然 RFC 建议服务器应该在没有 QUIT 的情况下也能正常工作，并且大多数 RFC 都这样做，但他们还建议客户端应该始终发送它并等待响应，那么……为什么不这样做呢？