下面为学习python使用SMTP发送邮件时的一段代码，运行时总是报错smtplib.SMTPDataError: (554, 'DT:SPM...，添加smtp.set_debuglevel(1)发现是调用smtp.sendmail（）时出错了，找了好多文章都说是 msg['Subject'] = sub msg['From'] = "username" + "<" + from_server + ">" msg['To'] = ";".join(to_list)内容有问题，仔细改了好几遍还是报一样的错，后来在发现有人使用邮件客户端时遇到同样的问题：
https://blog.csdn.net/jerry11112/article/details/81213162
是因为126服务器把发送的邮件当成垃圾邮件了，在收件人列表里面加上自己的邮箱，就可以成功发送了。折腾了一个晚上解决了之后感觉自己好无奈~~~
感觉解决办法有点儿low，不知道有没从代码上可以解决的办法，请指教。
# coding:utf-8
import smtplib
from email.mime.text import MIMEText
class SendEmail:
global host
global from_server
global password
host = "smtp.126.com"
from_server = "******@126.com"
password = "*******"
def send_email(self, sub, to_list, content):
msg = MIMEText(content, 'plain', 'utf-8')
msg['Subject'] = sub
msg['From'] = "username" + "<" + from_server + ">"
msg['To'] = ";".join(to_list)
smtp = smtplib.SMTP()
# smtp.set_debuglevel(1)
smtp.connect(host)
smtp.login(from_server, password)
smtp.sendmail(from_server, to_list, msg.as_string())
smtp.quit()
smtp.close()
if __name__ == '__main__':
sen = SendEmail()
sub = "测试"
to_list = ["******@126.com", "******@163.com"]
content = "第一封邮件"
sen.send_email(sub, to_list, content)
