python - 邮件会发送 3 次，而不是每个地址一次？

Question

我想出了一些对我来说似乎很奇怪的东西，并且我不确定到底要搜索什么。

import smtplib, openpyxl, sys
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.base import MIMEBase
from email import encoders

wb = openpyxl.load_workbook('Book1.xlsx') 
sheet = wb.get_sheet_by_name('Sheet1')    

lastCol = sheet.max_column  
latestMonth = sheet.cell(row=1, column=lastCol).value

recipients = []
unpaidMembers = {}   
for r in range(2, sheet.max_row + 1):
payment = sheet.cell(row=r, column=lastCol).value
if payment != 'Y':
    name = sheet.cell(row=r, column=1).value
    email = sheet.cell(row=r, column=2).value
    unpaidMembers[name] = email
    recipients.append(email)

fromaddr = "xxxx@xxxx.com"

for n in recipients:
    msg = MIMEMultipart()
    msg['From'] = fromaddr
    msg['To'] = n
    msg['Subject'] = "Hi"

    body = "This is a test mail"

    msg.attach(MIMEText(body, 'plain'))

    filename = "xxx.pdf"
    attachment = open("\\Users\xxx\xxx\xxx.pdf","rb")

    part = MIMEBase('application', 'octet-stream')
    part.set_payload((attachment).read())
    encoders.encode_base64(part)
    part.add_header('Content-Disposition', "attachment; filename= %s" % filename)

    msg.attach(part)

    smtp0bj = smtplib.SMTP('smtp-mail.outlook.com', 587)
    smtp0bj.ehlo()
    smtp0bj.starttls()
    smtp0bj.login(fromaddr, 'xxxxx')
    text = msg.as_string()
    smtp0bj.sendmail(fromaddr, recipients, text)
    smtp0bj.quit()

我猜测 for 循环被执行了 3 次(列表中有 3 项。我不知道如何让它只执行一次。

Answer 1

你基本上就是这么做的:

for n in recipients: # for each recipient
    smtp0bj.sendmail(fromaddr, recipients, text) # send mail to all recipients

因此，每次传递时，它都会将邮件发送给所有收件人。

因此，如果您有 3 个收件人，他们将每人收到 3 封邮件。

替换为:

smtp0bj.sendmail(fromaddr, n, text)

我也不确定，现在无法测试，但我相信“to”必须是一个列表。因此，如果上述解决方案不起作用，请尝试一下:

smtp0bj.sendmail(fromaddr, [n], text)