Python自动发邮件遭遇UnicodeEncodeError错误求助

我用Python编写的自动发邮件脚本，之前运行正常，后来突然出现编码错误：UnicodeEncodeError: 'ascii' codec can't encode characters in position 36-37: ordinal not in range(128)，之后每次执行都会触发这个错误，具体报错信息为：UnicodeEncodeError: 'ascii' codec can't encode character '\xa0' in position 36: ordinal not in range(128)。

我已经尝试了以下解决方法，但问题依然存在：

• 将发件人邮箱（EMAIL）、收件人邮箱（receiver_email）编码为UTF-8
• 读写CSV文件时明确指定encoding='utf-8'
• 确保邮件内容整体采用UTF-8格式

错误发生在代码行server.sendmail(EMAIL, [receiver_email, bcc_email], text)，完整的报错堆栈如下：

Traceback (most recent call last):
File "C:\Users\Desktop\program\automated mail system.py", line 111, in 
sendBulkMails()
File "C:\Users\Desktop\program\automated mail system.py", line 101, in sendBulkMails
server.sendmail(EMAIL,
File "C:\Users\Desktop\program\automated mail system.py", line 881, in sendmail
(code, resp) = self.rcpt(each, rcpt_options)
File "C:\Users\Desktop\program\automated mail system.py", line 553, in rcpt
self.putcmd("rcpt", "TO:%s%s" % (quoteaddr(recip), optionlist))
File "C:\Users\Desktop\program\automated mail system.py", line 378, in putcmd
self.send(f'{s}{CRLF}')
File "C:\Users\Desktop\program\automated mail system.py", line 357, in send
s = s.encode(self.command_encoding)
UnicodeEncodeError: 'ascii' codec can't encode character '\xa0' in position 36: ordinal not in range(128)

import smtplib
import ssl
import os
import csv
import fnmatch
import logging
import time
import shutil
logging.basicConfig(format='%(asctime)s %(message)s',level=logging.INFO)
from email import encoders
from email.mime.base import MIMEBase
from email.mime.application import MIMEApplication
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
from email.header import Header, decode_header
from email.utils import formataddr, encode_rfc2231


print("Send mails?")
premQuestion = input("Y/N:")
# get the date from folder name
if premQuestion.upper() == "Y":
    rootdir = r'D:\Mailsunsent'
    destdir = r'D:\Mailssent'
    if len(os.listdir(rootdir)) == 0:
        print("The selected folder is empty!\nVerify!")
    else:
        for file in os.listdir (rootdir):
            d = os.path.join(rootdir, file)
            target = os.path.join(destdir, file)
            if os.path.isdir(d):
                str(d)
                fday = d.split()[-2:]

# create the csv file after another

            with open('mailsload1.csv','r',newline='', encoding='utf-8') as csvin, \
open('mailsload2.csv','w',newline='', encoding='utf-8') as csvout:
                    reader =csv.reader(csvin, delimiter=';')
                    writer =csv.writer(csvout, delimiter=';')
                    
                    header = next(reader)
                    writer.writerow(header)

                    for name, nb, location, emailadress,senderMail,subject,passWord in reader:
                        writer.writerow([name,
                                         nb,
                                         f"D:\\Mailsunsent\\Mails to sent {' '.join(fday)}\\{name}",
                                         emailadress,
                                         senderMail,
                                         subject,
                                         passWord
                                         ])
                    
                with open('mailsload2.csv','r',newline='', encoding='utf-8') as csvin:

                    reader =csv.reader(csvin, delimiter=';')    
                    header = next(reader)
                    data=[]
                    
                    for row in reader:
                        dir_path = row[2]
                        count = len(fnmatch.filter(os.listdir(dir_path), '*.*'))
                        data.append(count)
                    linesNb = reader.line_num

                    with open('mailsload1.csv', 'r', encoding='utf-8') as file:
                        reader = csv.reader(file, delimiter=';')
                        rows = [row for row in reader]

                    i = 0
                    for row in rows:
                        for index, value in enumerate(row):
                            if value == '0':
                                row[index] = data[i]
                                i+=1
                    with open('mailsload2.csv', 'w', newline='', encoding='utf-8') as file:
                        writer = csv.writer(file,delimiter=';')
                        writer.writerows(rows)
                        
                    countMails = 0
                    with open("mailsload2.csv", 'r', newline='', encoding='utf-8') as file:
                        reader = csv.reader(file, delimiter=';')
                        header = next(reader)  # Skip header row
                        for row in reader:
                            if int(row[1]) > 0:
                                SMTP_SERVER = "some server mail"
                                PORT = 465
                                EMAIL = row[4]
                                PASSWORD = row[6]

                                subject = row[5]
                                html = """<!DOCTYPE html>
                                <html lang="en">
                                <head>
                                    <meta charset="UTF-8">
                                    <meta name="viewport" content="width=device-width, initial-scale=1.0">
                                    <title>Semnatura</title>
                                </head>
                                <body>
                                    <br>
                                    <br>
                                    <pre style="font-style: Arial;">         With pleasure,</pre>
                                    <p style="font-style: Arial;color: #00008B;"><b>Surname Name</b></p>
                                    <p style="font-style: Arial;"><b>Some firm</b></p>
                                    <p style="font-style: Arial;">Adress of firm</p>
                                    <p style="font-style: Arial;"><span style="color: #00008B;">Phone:</span> some phone number <span style="color: #00008B;">Email: </span><a  href="mailto:mail@mail.com">mail@mail.com</a></p>
                                </body>
                                </html>"""                          
                                bcc_email = row[4]
                                receiver_email = row[3]
                                
                                message = MIMEMultipart()                                 
                                message["From"]= Header(EMAIL, charset='utf-8', errors='strict')
                                message["To"]= Header(receiver_email, charset='utf-8', errors='strict')
                                message["Cc"]= Header(EMAIL, charset='utf-8', errors='strict')
                                message["Subject"]= Header(subject, charset='utf-8', errors='strict')

                                message.attach(MIMEText(html, "html", 'utf-8'))

                                dir_path = row[2]
                                files = fnmatch.filter(os.listdir(dir_path), '*.*')
                                for f in files:  # add files to the message
                                    file_path = os.path.join(dir_path, f)
                                    with open(file_path, "rb") as attachment:
                                        part = MIMEBase('application', 'octet-stream')
                                        part.set_payload((attachment).read())
                                        encoders.encode_base64(part)
                                        part.add_header('Content-Disposition', 'attachment', filename=f)
                                        message.attach(part)
                                        attachment.close()
                                
                                text = message.as_string()
                                context = ssl.create_default_context()

                                with smtplib.SMTP_SSL(SMTP_SERVER, PORT, context=context) as server:
                                    server.login(EMAIL, PASSWORD)
                                    server.sendmail(EMAIL,
                                                    [receiver_email,
                                                     bcc_email],
                                                    text
                                                    )
                                    logging.info(f" Successfully sent email to {receiver_email}")
                                    server.quit()

                                countMails += 1
                                time.sleep(20)
                    
                    print(f'S-au trimis {countMails} mailuri din data de {' '.join(fday)}.')
                    shutil.move(d, target)
else:
    quit()

内容的提问来源于stack exchange，提问作者MaxSteell