使用Mailgun Python API发送HTML邮件失败，文本邮件可正常发送

Got it, let's get your HTML emails sending smoothly! The issue with your current code is that it only specifies a plain text version of the email using the text parameter. To send HTML content, you just need to add an html field to your data payload. I also fixed a small bug with the attachment handling that could cause errors when no filename is provided.

Here's the modified function:

def send_email(mailtext, htmltext="", filename=""):
    # Only include attachment if filename is provided
    files = [("attachment", open(filename, "rb"))] if filename else []
    
    requests.post(
        "https://api.mailgun.net/v3/mydomain.in/messages",
        auth=("api", "key-1234"),
        files=files,
        data={
            "from": "Credit Card Manager <creditcards@mydomain.in>",
            "to": ["bob@mydomain.in"],
            "subject": "Summary of Credit Card payments due",
            "text": mailtext,  # Plain text fallback for non-HTML clients
            "html": htmltext   # Your HTML content goes here
        }
    )

How to Use It #

Call the function with both plain text and HTML content to ensure compatibility across all email clients:

# Plain text version (for clients that don't support HTML)
plain_text = "Hi Bob, here's your credit card payment summary... (plain text details)"

# HTML version with formatting
html_content = """
<html>
  <body>
    <h1 style="color: #2c3e50;">Credit Card Payment Summary</h1>
    <p>Hi Bob,</p>
    <p>Here’s your upcoming payment breakdown:</p>
    <table style="border-collapse: collapse; width: 100%;">
      <tr>
        <th style="border: 1px solid #ddd; padding: 8px;">Card</th>
        <th style="border: 1px solid #ddd; padding: 8px;">Amount Due</th>
        <th style="border: 1px solid #ddd; padding: 8px;">Due Date</th>
      </tr>
      <tr>
        <td style="border: 1px solid #ddd; padding: 8px;">Card 1</td>
        <td style="border: 1px solid #ddd; padding: 8px;">$500.00</td>
        <td style="border: 1px solid #ddd; padding: 8px;">15th October</td>
      </tr>
    </table>
    <p>Thanks,<br>Credit Card Manager</p>
  </body>
</html>
"""

# Send the email with both formats
send_email(plain_text, html_content)

Key Tips: #

• Including both text and html ensures your email works for every recipient—HTML-capable clients show the formatted version, while others use the plain text fallback.
• Double-check your HTML for well-formed tags (no unclosed elements) to avoid rendering glitches.
• Use rb (read binary) mode when opening attachment files to handle all file types correctly.

内容的提问来源于stack exchange，提问作者Joel G Mathew