Python Gmail API: Adding clickable hyperlinks to existing emails without corruption

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1

I’m trying to create a Python script that can add clickable hyperlinks to emails that already exist in Gmail. I’ve got a similar script working that resizes large images in emails to save space.

My current approach is to:

  1. Fetch the email
  2. Edit the copy
  3. Write it back with the same threadId
  4. Delete the original email

The problem is that when I add a hyperlink, it doesn’t show up as clickable in the Gmail web interface. The ‘show original’ function in Gmail reveals that the href attribute is missing an equals sign.

Here’s a simplified version of my code:

def add_link_to_email(service, email_id):
    # Fetch email
    email = service.users().messages().get(userId='me', id=email_id, format='raw').execute()
    
    # Decode email content
    email_content = base64.urlsafe_b64decode(email['raw']).decode('utf-8')
    
    # Parse email content
    msg = email.message_from_string(email_content)
    
    # Find HTML part and add link
    for part in msg.walk():
        if part.get_content_type() == 'text/html':
            html = part.get_payload()
            soup = BeautifulSoup(html, 'html.parser')
            new_link = soup.new_tag('a', href='http://example.com')
            new_link.string = 'Example Link'
            soup.body.insert(0, new_link)
            part.set_payload(str(soup))
    
    # Encode modified email
    modified_email = base64.urlsafe_b64encode(msg.as_string().encode()).decode()
    
    # Update email
    updated_email = {'raw': modified_email, 'threadId': email['threadId']}
    service.users().messages().insert(userId='me', body=updated_email).execute()
    service.users().messages().delete(userId='me', id=email_id).execute()

Any ideas on why Gmail might be mangling these messages when viewed or forwarded from the web interface, but not when accessed via the API?

2

I’ve encountered similar issues when modifying existing Gmail emails through the API. A potential fix is to use the modify method instead of deleting and reinserting emails. Updating the email in place may help preserve essential formatting details, such as the proper representation of the href attribute.

For instance, you could replace your insert and delete calls with:

service.users().messages().modify(userId='me', id=email_id, body={'raw': modified_email}).execute()

It is also advisable to ensure that your HTML content is thoroughly encoded and well-formed to avoid Gmail’s stringent formatting adjustments.

3

hey creativePainter33, i’ve dealt with similar stuff before. try using the ‘modify’ method instead of deleting and reinserting. it might help keep the formatting intact. also, double-check your html encoding - gmail can be picky bout that stuff. good luck!

4

I’ve had my fair share of battles with the Gmail API, and I can relate to your frustration. One thing that’s worked for me is using the ‘modify’ method instead of the delete-and-insert approach. It tends to preserve more of the original email structure.

Another trick I’ve found helpful is to use inline CSS for styling your links. Sometimes Gmail strips out certain attributes, but inline styles usually stick. Something like this:

<a href='http://example.com' style='color: blue; text-decoration: underline;'>Example Link</a>

Also, make sure you’re properly encoding special characters in your URLs. I’ve seen cases where ampersands and other symbols caused issues if not properly encoded.

Lastly, if all else fails, you might want to consider creating a completely new email and copying over the content, rather than modifying the existing one. It’s not ideal, but sometimes it’s the only way to ensure everything renders correctly.