该问题产生的原因是iOS端默认的编码方式为UTF-8，而CSV文件可能采用了不同的编码方式，导致了乱码问题。解决方法是在发送邮件时，指定CSV文件的编码方式为UTF-8，可通过以下代码实现：

# 导入模块
import boto3
from botocore.exceptions import ClientError

# AWS SES配置
AWS_REGION = "us-west-2"
SENDER = "sender@example.com"
RECIPIENT = "recipient@example.com"
SUBJECT = "Test email with csv attachment"
BODY_TEXT = "Please see the attachment for csv data."
charset = "UTF-8"

# 读取csv文件
with open("file.csv", "rb") as f:
    data = f.read()

# 构造SES参数
att = {
    'Data': data,
    'Charset': charset,
    'Filename': 'file.csv'
}
msg = {
    'Subject': {
        'Data': SUBJECT,
        'Charset': charset
    },
    'Body': {
        'Text': {
            'Data': BODY_TEXT,
            'Charset': charset
        }
    },
    'Source': SENDER,
    'Destinations': [RECIPIENT],
    'Attachments': [att]
}

# 发送邮件
try:
    ses = boto3.client('ses', region_name=AWS_REGION)
    response = ses.send_email(
        Destination={
            'ToAddresses': msg["Destinations"]
        },
        Message=msg,
        Source=msg["Source"]
    )
    print("Email sent! Message ID:", response['MessageId'])
except ClientError as e:
    print(e.response['Error']['Message'])