要在AWS SES中添加自定义头部到邮件，可以使用AWS SDK提供的SendRawEmail方法来实现。以下是一个使用AWS SDK for Python（Boto3）的代码示例：

import boto3
from botocore.exceptions import ClientError

def send_email_with_custom_header(sender, recipient, subject, body, custom_header):
    # Create a new SES client
    ses_client = boto3.client('ses')

    # Create the message
    msg = f"""From: {sender}
To: {recipient}
Subject: {subject}
{custom_header}
{body}
"""

    # Send the email
    try:
        response = ses_client.send_raw_email(
            Source=sender,
            Destinations=[recipient],
            RawMessage={'Data': msg}
        )
        print("Email sent successfully!")
    except ClientError as e:
        print(f"Email sending failed: {e.response['Error']['Message']}")

# Example usage
sender = "sender@example.com"
recipient = "recipient@example.com"
subject = "Test Email"
body = "This is a test email."
custom_header = "X-Custom-Header: Custom Value"

send_email_with_custom_header(sender, recipient, subject, body, custom_header)

在上述示例中，我们首先创建一个新的SES客户端。然后，我们使用提供的发件人、收件人、主题、邮件正文和自定义头部创建邮件消息。最后，我们使用send_raw_email方法发送带有自定义头部的原始邮件。

请注意，此示例假设您已经正确配置了AWS SDK并具有相应的AWS凭证。