AWS Lambda python 发送邮件

Question

我正在尝试将收到的电子邮件转发到我的 route53 域。 我想将此邮件存储到我的 S3 存储桶（这有效）并将其转发到另一封邮件（这部分有效）。 我已经复制了一个 python 脚本来在 Lambda 中设置它。 该脚本成功转发了我的电子邮件，当时它是通过 gmail 从经典计算机使用 Firefox 发送的。 但是，当我从我的 iphone 上尝试时它不起作用......

我有以下错误：

[ERROR] AttributeError: 'bytes' object has no attribute 'encode'
Traceback (most recent call last):
  File "/var/task/lambda_function.py", line 200, in lambda_handler
    message = create_message(file_dict)
  File "/var/task/lambda_function.py", line 134, in create_message
    body = MIMEText(mailobject.get_payload(decode=True), 'UTF-8')
  File "/var/lang/lib/python3.7/email/mime/text.py", line 34, in __init__
    _text.encode('us-ascii')

这是我的代码：

# Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# This file is licensed under the Apache License, Version 2.0 (the "License").
# You may not use this file except in compliance with the License. A copy of the
# License is located at
#
# http://aws.amazon.com/apache2.0/
#
# This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS
# OF ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

import os
import boto3
import email
import re
import html
from botocore.exceptions import ClientError
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.application import MIMEApplication
from email.mime.image import MIMEImage

os.environ['MailS3Prefix'] =        #
os.environ['Region'] =              #
os.environ['MailS3Bucket'] =        #
os.environ['MailSender'] =          #
os.environ['MailRecipient'] =       #

region = os.environ['Region']

def get_message_from_s3(message_id):

    incoming_email_bucket = os.environ['MailS3Bucket']
    incoming_email_prefix = os.environ['MailS3Prefix']

    if incoming_email_prefix:
        object_path = (incoming_email_prefix + "/" + message_id)
    else:
        object_path = message_id

    object_http_path = (f"http://s3.console.aws.amazon.com/s3/object/{incoming_email_bucket}/{object_path}?region={region}")

    # Create a new S3 client.
    client_s3 = boto3.client("s3")

    # Get the email object from the S3 bucket.
    object_s3 = client_s3.get_object(Bucket=incoming_email_bucket,
        Key=object_path)
    # Read the content of the message.
    file = object_s3['Body'].read()

    file_dict = {
        "file": file,
        "path": object_http_path
    }

    return file_dict

def create_message(file_dict):

    stringMsg = file_dict['file'].decode('utf-8')

    # Create a MIME container.
    msg = MIMEMultipart('alternative')

    sender = os.environ['MailSender']
    recipient = os.environ['MailRecipient']

    # Parse the email body.
    mailobject = email.message_from_string(file_dict['file'].decode('utf-8'))
    #print(mailobject.as_string())

    # Get original sender for reply-to
    from_original = mailobject['Return-Path']
    from_original = from_original.replace('<', '');
    from_original = from_original.replace('>', '');
    print(from_original)

    # Create a new subject line.
    subject = mailobject['Subject']
    print(subject)

    if mailobject.is_multipart():

        #The quick and dirty way.  If you don't like this, use the for loop below it.
        index = stringMsg.find('Content-Type: multipart/')
        stringBody = stringMsg[index:]
        #print(stringBody)
        stringData = 'Subject: ' + subject + '\nTo: ' + sender + '\nreply-to: ' + from_original + '\n' + stringBody

        message = {
            "Source": sender,
            "Destinations": recipient,
            "Data": stringData
        }
        return message

        for part in mailobject.walk():
            ctype = part.get_content_type()
            cdispo = str(part.get('Content-Disposition'))

            # case for each common content type
            if ctype == 'text/plain' and 'attachment' not in cdispo:
                bodyPart = MIMEText(part.get_payload(decode=True), 'plain', part.get_content_charset())
                msg.attach(bodyPart)

            if ctype == 'text/html' and 'attachment' not in cdispo:
                mt = MIMEText(part.get_payload(decode=True), 'html', part.get_content_charset())
                email.encoders.encode_quopri(mt)
                del mt['Content-Transfer-Encoding']
                mt.add_header('Content-Transfer-Encoding', 'quoted-printable')
                msg.attach(mt)

            if 'attachment' in cdispo and 'image' in ctype:
                mi = MIMEImage(part.get_payload(decode=True), ctype.replace('image/', ''))
                del mi['Content-Type']
                del mi['Content-Disposition']
                mi.add_header('Content-Type', ctype)
                mi.add_header('Content-Disposition', cdispo)
                msg.attach(mi)

            if 'attachment' in cdispo and 'application' in ctype:
                ma = MIMEApplication(part.get_payload(decode=True), ctype.replace('application/', ''))
                del ma['Content-Type']
                del ma['Content-Disposition']
                ma.add_header('Content-Type', ctype)
                ma.add_header('Content-Disposition', cdispo)
                msg.attach(ma)


    # not multipart - i.e. plain text, no attachments, keeping fingers crossed
    else:
        body = MIMEText(mailobject.get_payload(decode=True), 'UTF-8')
        msg.attach(body)

    # The file name to use for the attached message. Uses regex to remove all
    # non-alphanumeric characters, and appends a file extension.
    filename = re.sub('[^0-9a-zA-Z]+', '_', subject_original)

    # Add subject, from and to lines.
    msg['Subject'] = subject
    msg['From'] = sender
    msg['To'] = recipient
    msg['reply-to'] = mailobject['Return-Path']

    # Create a new MIME object.
    att = MIMEApplication(file_dict["file"], filename)
    att.add_header("Content-Disposition", 'attachment', filename=filename)

    # Attach the file object to the message.
    msg.attach(att)

    message = {
        "Source": sender,
        "Destinations": recipient,
        "Data": msg.as_string()
    }

    return message

def send_email(message):
    aws_region = os.environ['Region']

    # Create a new SES client.
    client_ses = boto3.client('ses', region)

    # Send the email.
    try:
        #Provide the contents of the email.
        response = client_ses.send_raw_email(
            Source=message['Source'],
            Destinations=[
                message['Destinations']
            ],
            RawMessage={
                'Data':message['Data']
            }
        )

    # Display an error if something goes wrong.
    except ClientError as e:
        print('Send email ClientError Exception')
        output = e.response['Error']['Message']
    else:
        output = "Email sent! Message ID: " + response['MessageId']

    return output

def lambda_handler(event, context):
    # Get the unique ID of the message. This corresponds to the name of the file
    # in S3.
    message_id = event['Records'][0]['ses']['mail']['messageId']
    print(f"Received message ID {message_id}")

    # Retrieve the file from the S3 bucket.
    file_dict = get_message_from_s3(message_id)

    # Create the message.
    message = create_message(file_dict)

    # Send the email and print the result.
    result = send_email(message)
    print(result)

谢谢你的麻！

Answer 1

借助上面 jarmod 的评论，我可以让它工作。我不是这方面的专家，因此代码可能需要一些改进。电子邮件正文还包括 html 标签。但至少它已经交付了。

如果解码电子邮件仍然失败，错误消息将显示在您的 CloudWatch 日志中。您还将收到一封包含错误消息的电子邮件。

payload = mailobject.get_payload(decode=True)
try:
    decodedPayload = payload.decode()
    body = MIMEText(decodedPayload, 'UTF-8')
    msg.attach(body)
except Exception as error:
    errorMsg = "An error occured when decoding the email payload:\n" + str(error)
    print(errorMsg)
    body = errorMsg + "\nPlease download it manually from the S3 bucket."
    msg.attach(MIMEText(body, 'plain'))

您可以自行决定将哪些信息添加到错误电子邮件中，例如主题或发件人地址。

另一个提示：使用上面的代码你会得到一个错误，因为subject_original 是未定义的。只需删除以下行。

# The file name to use for the attached message. Uses regex to remove all
# non-alphanumeric characters, and appends a file extension.
filename = re.sub('[^0-9a-zA-Z]+', '_', subject_original)

# Create a new MIME object.
att = MIMEApplication(file_dict["file"], filename)
att.add_header("Content-Disposition", 'attachment', filename=filename)

# Attach the file object to the message.
msg.attach(att)

据我了解，此代码应该将原始电子邮件添加为附件，这不是我想要的。