Access and Parse Outlook Thunderbird Mailbox with Python   

In this guide, you'll see how to access and parse emails from Outlook and Thunderbird mailboxes using Python.

Here you can find the short answer:

(1) Access Outlook with win32com

import win32com.client
outlook = win32com.client.Dispatch("Outlook.Application")
inbox = outlook.GetNamespace("MAPI").GetDefaultFolder(6)

(2) Parse Thunderbird mailbox

import mailbox
mbox = mailbox.mbox('Inbox')
for message in mbox:
    print(message['subject'])

(3) Parse email with email library

import email
msg = email.message_from_string(raw_email)
print(msg['From'], msg['Subject'])

So let's see how to connect to email clients and extract messages programmatically.

1: Access Outlook mailbox on Windows

Let's start with accessing Outlook emails on Windows using the win32com.client library:

Install required package:

pip install pywin32

Basic Outlook connection:

import win32com.client

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")

inbox = outlook.GetDefaultFolder(6)

messages = inbox.Items
messages.Sort("[ReceivedTime]", True)

print(f"Total emails in Inbox: {len(messages)}")

for i, message in enumerate(messages[:5], 1):
    print(f"\n--- Email {i} ---")
    print(f"From: {message.SenderName}")
    print(f"Subject: {message.Subject}")
    print(f"Received: {message.ReceivedTime}")
    print(f"Size: {message.Size / 1024:.2f} KB")

result will be:

Total emails in Inbox: 1247

--- Email 1 ---
From: John Smith
Subject: Q4 Budget Review Meeting
Received: 2024-12-15 09:30:00
Size: 12.45 KB

--- Email 2 ---
From: Sarah Johnson
Subject: Project Alpha Status Update
Received: 2024-12-15 08:15:00
Size: 8.92 KB

--- Email 3 ---
From: Microsoft Teams
Subject: New message in Engineering channel
Received: 2024-12-14 16:45:00
Size: 5.67 KB

Outlook folder indices:

• 3 = Deleted Items
• 4 = Outbox
• 5 = Sent Items
• 6 = Inbox
• 9 = Calendar
• 10 = Contacts
• 16 = Drafts

2: Extract email content and attachments

Access email body, attachments, and metadata from Outlook messages:

import win32com.client
import os

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
inbox = outlook.GetDefaultFolder(6)

messages = inbox.Items
messages.Sort("[ReceivedTime]", True)

attachment_folder = "C:/email_attachments/"
os.makedirs(attachment_folder, exist_ok=True)

for message in messages[:10]:
    print(f"\nSubject: {message.Subject}")
    print(f"From: {message.SenderEmailAddress}")
    print(f"To: {message.To}")
    print(f"CC: {message.CC}")
    print(f"Date: {message.ReceivedTime}")
    
    print(f"\nBody preview (first 200 chars):")
    body = message.Body if hasattr(message, 'Body') else ""
    print(body[:200] + "...")
    
    if message.Attachments.Count > 0:
        print(f"\nAttachments ({message.Attachments.Count}):")
        for attachment in message.Attachments:
            print(f"  - {attachment.FileName}")
            
            attachment_path = os.path.join(attachment_folder, attachment.FileName)
            attachment.SaveAsFile(attachment_path)
            print(f"    Saved to: {attachment_path}")

print(f"\n✓ Processed {min(10, len(messages))} emails")

result:

Subject: Invoice #12345 - December 2024
From: [email protected]
To: [email protected]
CC: 
Date: 2024-12-15 10:20:00

Body preview (first 200 chars):
Dear John,

Please find attached your invoice for December 2024. The total amount due is $1,250.00. Payment is due by December 31st.

Thank you for your business.

Best regards,
Accounting Team...

Attachments (2):
  - Invoice_12345.pdf
    Saved to: C:/email_attachments/Invoice_12345.pdf
  - Payment_Details.xlsx
    Saved to: C:/email_attachments/Payment_Details.xlsx

✓ Processed 10 emails

3: Parse Thunderbird mailbox files

Thunderbird stores emails in mbox format, which can be accessed using Python's built-in mailbox library:

Locate Thunderbird profile:

• Windows: C:\Users\YourName\AppData\Roaming\Thunderbird\Profiles\
• macOS: ~/Library/Thunderbird/Profiles/
• Linux: ~/.thunderbird/

Parse mbox file:

import mailbox
import email
from email.header import decode_header

mbox_path = r"C:\Users\YourName\AppData\Roaming\Thunderbird\Profiles\xxx.default\Mail\Local Folders\Inbox"

mbox = mailbox.mbox(mbox_path)

print(f"Total messages in mailbox: {len(mbox)}")

for idx, message in enumerate(mbox, 1):
    subject = message['subject']
    from_addr = message['from']
    date = message['date']
    
    subject_decoded = decode_header(subject)[0][0]
    if isinstance(subject_decoded, bytes):
        subject_decoded = subject_decoded.decode()
    
    print(f"\n--- Message {idx} ---")
    print(f"From: {from_addr}")
    print(f"Subject: {subject_decoded}")
    print(f"Date: {date}")
    
    if message.is_multipart():
        for part in message.walk():
            content_type = part.get_content_type()
            if content_type == "text/plain":
                body = part.get_payload(decode=True).decode()
                print(f"Body preview: {body[:150]}...")
                break
    else:
        body = message.get_payload(decode=True).decode()
        print(f"Body preview: {body[:150]}...")
    
    if idx >= 5:
        break

print("\n✓ Mailbox parsing complete")

result:

Total messages in mailbox: 3892

--- Message 1 ---
From: Sarah Chen <[email protected]>
Subject: Team Meeting Notes - Project Alpha
Date: Mon, 16 Dec 2024 14:30:25 +0000

Body preview: Hi Team,

Here are the key takeaways from today's meeting:

1. Sprint 12 completed successfully
2. Demo scheduled for Friday
3. Client feedback session...

--- Message 2 ---
From: GitHub <[email protected]>
Subject: [repo-name] Pull Request #234 merged
Date: Mon, 16 Dec 2024 09:15:42 +0000

Body preview: Your pull request "Add authentication middleware" has been merged into main branch by @john-doe.

Changes included:
- Added JWT token validation
- Implement...

✓ Mailbox parsing complete

4: Filter and search emails by criteria

Implement email filtering to find specific messages based on sender, subject, date, or content:

import win32com.client
from datetime import datetime, timedelta

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
inbox = outlook.GetDefaultFolder(6)

def search_emails(folder, sender=None, subject_keyword=None, days_back=7):
    """
    Search emails with multiple criteria
    """
    messages = folder.Items
    
    date_filter = datetime.now() - timedelta(days=days_back)
    date_filter_str = date_filter.strftime("%m/%d/%Y")
    
    filter_str = f"[ReceivedTime] >= '{date_filter_str}'"
    
    if sender:
        filter_str += f" AND [SenderEmailAddress] = '{sender}'"
    
    filtered = messages.Restrict(filter_str)
    
    results = []
    for message in filtered:
        if subject_keyword:
            if subject_keyword.lower() in message.Subject.lower():
                results.append(message)
        else:
            results.append(message)
    
    return results

print("=== Search Example 1: Emails from specific sender (last 7 days) ===")
sender_emails = search_emails(inbox, sender="[email protected]")
print(f"Found {len(sender_emails)} emails from [email protected]")
for msg in sender_emails[:3]:
    print(f"  - {msg.Subject} ({msg.ReceivedTime})")

print("\n=== Search Example 2: Emails with 'invoice' in subject (last 30 days) ===")
invoice_emails = search_emails(inbox, subject_keyword="invoice", days_back=30)
print(f"Found {len(invoice_emails)} emails with 'invoice' in subject")
for msg in invoice_emails[:3]:
    print(f"  - {msg.Subject} ({msg.SenderName})")

print("\n=== Search Example 3: Recent meeting invites ===")
meeting_emails = search_emails(inbox, subject_keyword="meeting", days_back=14)
print(f"Found {len(meeting_emails)} emails with 'meeting' in subject")
for msg in meeting_emails[:3]:
    print(f"  - {msg.Subject} ({msg.ReceivedTime})")

result:

=== Search Example 1: Emails from specific sender (last 7 days) ===
Found 12 emails from [email protected]
  - Weekly Status Report (2024-12-15 16:30:00)
  - Q4 Budget Approval (2024-12-14 10:15:00)
  - Team Lunch This Friday (2024-12-13 09:45:00)

=== Search Example 2: Emails with 'invoice' in subject (last 30 days) ===
Found 8 emails with 'invoice' in subject
  - Invoice #12345 - December 2024 (Accounting Department)
  - Payment Received - Invoice #12300 (Finance Team)
  - Overdue Invoice Reminder (Billing System)

=== Search Example 3: Recent meeting invites ===
Found 15 emails with 'meeting' in subject
  - Team Meeting Notes - Project Alpha (2024-12-16 14:30:00)
  - All Hands Meeting Reminder (2024-12-15 08:00:00)
  - Client Meeting Rescheduled (2024-12-13 11:20:00)

5: Parse email headers and extract metadata

Extract detailed email headers, reply-to addresses, and routing information:

import win32com.client
import email

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
inbox = outlook.GetDefaultFolder(6)

message = inbox.Items[0]

print(f"Subject: {message.Subject}")
print(f"From: {message.SenderName} <{message.SenderEmailAddress}>")
print(f"To: {message.To}")
print(f"CC: {message.CC}")
print(f"BCC: {message.BCC}")
print(f"Reply To: {message.ReplyRecipients}")
print(f"Importance: {message.Importance}")
print(f"Sensitivity: {message.Sensitivity}")
print(f"Size: {message.Size / 1024:.2f} KB")
print(f"Unread: {message.UnRead}")
print(f"Received Time: {message.ReceivedTime}")
print(f"Sent On: {message.SentOn}")
print(f"Message Class: {message.MessageClass}")

try:
    headers = message.PropertyAccessor.GetProperty(
        "http://schemas.microsoft.com/mapi/proptag/0x007D001E"
    )
    print(f"\nFull Headers:\n{headers}")
except:
    print("\nFull headers not available for this message")

if message.Categories:
    print(f"\nCategories: {message.Categories}")

if hasattr(message, 'FlagRequest'):
    print(f"Flag Status: {message.FlagRequest}")

result:

Subject: Q4 Budget Review Meeting
From: John Smith <[email protected]>
To: [email protected]
CC: [email protected]
BCC: 
Reply To: <[email protected]>
Importance: 1
Sensitivity: 0
Size: 12.45 KB
Unread: False
Received Time: 2024-12-15 09:30:00
Sent On: 2024-12-15 09:29:45
Message Class: IPM.Note

Full Headers:
Received: from mail.company.com (10.0.1.5) by exchange.company.com
Date: Mon, 15 Dec 2024 09:29:45 -0800
From: John Smith <[email protected]>
To: [email protected]
Subject: Q4 Budget Review Meeting
Message-ID: <[email protected]>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"

Categories: Important, Work
Flag Status: Follow up

6: Export emails to CSV for analysis

Create a CSV export of email metadata for reporting and analysis:

import win32com.client
import csv
from datetime import datetime

outlook = win32com.client.Dispatch("Outlook.Application").GetNamespace("MAPI")
inbox = outlook.GetDefaultFolder(6)

messages = inbox.Items
messages.Sort("[ReceivedTime]", True)

csv_file = "outlook_emails_export.csv"

with open(csv_file, 'w', newline='', encoding='utf-8') as file:
    writer = csv.writer(file)
    
    writer.writerow([
        'Subject', 'From', 'To', 'Received Date', 
        'Size (KB)', 'Has Attachments', 'Attachment Count', 'Unread'
    ])
    
    for i, message in enumerate(messages[:100], 1):
        try:
            writer.writerow([
                message.Subject,
                message.SenderEmailAddress,
                message.To,
                message.ReceivedTime.strftime('%Y-%m-%d %H:%M:%S'),
                f"{message.Size / 1024:.2f}",
                'Yes' if message.Attachments.Count > 0 else 'No',
                message.Attachments.Count,
                'Yes' if message.UnRead else 'No'
            ])
            
            if i % 25 == 0:
                print(f"Processed {i} emails...")
                
        except Exception as e:
            print(f"Error processing message: {e}")
            continue

print(f"\n✓ Exported {i} emails to {csv_file}")

result:

Processed 25 emails...
Processed 50 emails...
Processed 75 emails...
Processed 100 emails...

✓ Exported 100 emails to outlook_emails_export.csv

CSV Output:

Common Use Cases

Email Automation: Auto-download attachments, archive old emails, organize by sender

Data Extraction: Parse order confirmations, invoices, shipping notifications

Reporting: Generate email activity reports, response time analysis

Backup: Export emails to local storage for archival

Integration: Connect Outlook/Thunderbird to CRM, ticketing systems, databases

Monitoring: Track emails from specific senders, flag urgent messages

Comparison: Outlook vs Thunderbird Access

Best Practices

• Close connections properly to avoid locking mailbox files
• Handle errors with try-except for malformed emails
• Limit batch size when processing thousands of emails
• Use filters to reduce processing time
• Cache results for repeated access to same emails
• Don't modify Thunderbird mbox files while Thunderbird is running
• Avoid hardcoding mailbox paths - use environment variables
• Don't process all emails at once - use pagination

Resources

• pywin32 Documentation
• Python mailbox Library
• Python email Library
• Outlook MAPI Reference