Filtering out signature images when retrieving emails using Python Gmail API

Other Questions Gmail
1

I’m working with the Gmail API in Python and need help with a specific issue. When I fetch email messages, I’m getting all the attachments including the inline images that are part of email signatures. I want to exclude these signature images from my results.

I know that Google Apps Script has a feature to skip inline images, but I’m not sure how to achieve the same thing in Python. Is there a way to filter out signature images when processing email data?

Here’s the Python code I’m currently using:

email_data = (
    gmail_service.users()
    .messages()
    .get(userId="me", id=msg_id, format="full")
    .execute()
)

Any suggestions on how to modify this approach to ignore signature images would be really helpful.

2

Check the filename patterns too - signature images usually have generic names like ‘image001.png’ or company logos. Also look at the cid references in the html body. If an image isn’t referenced there, it’s probably not a signature. This worked for me with the same problem last month.

3

Here’s what worked for me - check the message structure hierarchy. Signature images usually get embedded in the HTML part of multipart/alternative messages and follow predictable positioning patterns. When you’re parsing the email payload, signature images typically show up at the end of the message parts sequence with HTML img tags that have cid attributes. I’ve found that looking at the Content-Location header plus where the attachment sits in the message structure helps separate signature images from real attachments. Signature images also tend to have the same dimensions and show up in every email from that sender, so tracking these patterns across multiple messages improves your filtering accuracy.

4

I encountered a similar challenge with the Gmail API processing email attachments. A good strategy is to examine the Content-Disposition field for each attachment; signature images often have ‘inline’ designated rather than ‘attachment’. Additionally, these images usually possess a Content-ID header linking them to the email body. While iterating through the email’s parts, filter for attachments with ‘image’ in their mimeType, and confirm that they have both ‘Content-Disposition: inline’ and a ‘Content-ID’. It may also be helpful to check for small file sizes, as signature images tend to be under 50KB. This method significantly reduced the number of irrelevant images in my results.