EML to Excel or CSV File

'; return; } fileList.innerHTML = this.files.map((file, index) => ` `).join(''); } removeFile(index) { this.files.splice(index, 1); this.updateFileList(); this.updateButtons(); if (this.files.length === 0) { this.hidePreview(); document.getElementById('downloadButton').disabled = true; } } updateButtons() { const processButton = document.getElementById('processButton'); const clearButton = document.getElementById('clearButton'); const hasFiles = this.files.length > 0; processButton.disabled = !hasFiles; clearButton.disabled = !hasFiles; } async processFiles() { const progressSection = document.getElementById('progressSection'); const progressBar = document.getElementById('progressBar'); const progressText = document.getElementById('progressText'); progressSection.classList.remove('hidden'); this.processedData = []; let processedCount = 0; try { for (let i = 0; i < this.files.length; i++) { const file = this.files[i]; progressText.textContent = `Processing ${file.name} (${i + 1}/${this.files.length})`; progressBar.value = (i / this.files.length); try { const emailData = await this.parseEMLFile(file); this.processedData.push(emailData); processedCount++; } catch (error) { console.error(`Error processing ${file.name}:`, error); this.showError(`Error processing ${file.name}: ${error.message}`); } // Small delay for UI responsiveness await new Promise(resolve => setTimeout(resolve, 50)); } progressBar.value = 1; progressText.textContent = `Processing complete! Successfully processed ${processedCount}/${this.files.length} files.`; setTimeout(() => { progressSection.classList.add('hidden'); if (this.processedData.length > 0) { this.showPreview(); document.getElementById('downloadButton').disabled = false; this.showSuccess(`Successfully processed ${processedCount} EML files. Data is ready for download.`); } else { this.showError('No files were successfully processed. Please check your EML files and try again.'); } }, 1000); } catch (error) { progressSection.classList.add('hidden'); this.showError('An error occurred during processing. Please try again.'); console.error('Processing error:', error); } } async parseEMLFile(file) { return new Promise((resolve, reject) => { const reader = new FileReader(); reader.onload = (e) => { try { const emlContent = e.target.result; const parsed = this.parseEMLContent(emlContent); resolve({ filename: file.name, fileSize: this.formatFileSize(file.size), ...parsed }); } catch (error) { reject(error); } }; reader.onerror = () => reject(new Error('Failed to read file')); reader.readAsText(file, 'utf-8'); }); } parseEMLContent(content) { const headers = {}; const lines = content.split(/\r?\n/); let headerSection = true; let bodyLines = []; let currentHeader = null; for (let line of lines) { if (headerSection) { if (line.trim() === '') { headerSection = false; continue; } if (line.match(/^\s/)) { // Continuation of previous header if (currentHeader && headers[currentHeader]) { headers[currentHeader] += ' ' + line.trim(); } } else { const colonIndex = line.indexOf(':'); if (colonIndex > 0) { currentHeader = line.substring(0, colonIndex).toLowerCase().trim(); headers[currentHeader] = line.substring(colonIndex + 1).trim(); } } } else { bodyLines.push(line); } } const body = bodyLines.join('\n'); const plainTextBody = this.extractPlainText(body, headers['content-type'] || ''); return { from: this.decodeHeader(headers.from || ''), to: this.decodeHeader(headers.to || ''), cc: this.decodeHeader(headers.cc || ''), bcc: this.decodeHeader(headers.bcc || ''), subject: this.decodeHeader(headers.subject || ''), date: this.decodeHeader(headers.date || ''), messageId: headers['message-id'] || '', contentType: headers['content-type'] || '', xMailer: headers['x-mailer'] || '', returnPath: headers['return-path'] || '', received: headers['received'] || '', mimeVersion: headers['mime-version'] || '', body: plainTextBody, bodyPreview: plainTextBody.substring(0, 150).replace(/\s+/g, ' ').trim() + (plainTextBody.length > 150 ? '...' : ''), rawHeaders: Object.keys(headers).map(key => `${key}: ${headers[key]}`).join('\n'), fullContent: content }; } decodeHeader(header) { if (!header) return ''; // Decode RFC 2047 encoded-words return header.replace(/=\?([^?]+)\?([BQ])\?([^?]*)\?=/gi, (match, charset, encoding, encoded) => { try { if (encoding.toLowerCase() === 'b') { return atob(encoded); } else if (encoding.toLowerCase() === 'q') { return encoded.replace(/[=]([0-9A-F]{2})/gi, (m, hex) => String.fromCharCode(parseInt(hex, 16)) ).replace(/_/g, ' '); } } catch (e) { console.warn('Header decode error:', e); } return match; }).replace(/\s+/g, ' ').trim(); } extractPlainText(body, contentType) { if (!body) return ''; // Handle quoted-printable encoding body = body.replace(/=\r?\n/g, '').replace(/=([0-9A-F]{2})/gi, (match, hex) => { try { return String.fromCharCode(parseInt(hex, 16)); } catch (e) { return match; } }); // Handle HTML content if (contentType.toLowerCase().includes('text/html')) { return body .replace(/]*>.*?<\/style>/gis, '') .replace(/]*>.*?<\/script>/gis, '') .replace(/<[^>]*>/g, ' ') .replace(/ /gi, ' ') .replace(/&/gi, '&') .replace(/</gi, '<') .replace(/>/gi, '>') .replace(/"/gi, '"') .replace(/'/gi, "'") .replace(/\s+/g, ' ') .trim(); } return body.replace(/\s+/g, ' ').trim(); } showPreview() { const previewSection = document.getElementById('previewSection'); const previewTableBody = document.getElementById('previewTableBody'); if (this.processedData.length === 0) { previewSection.classList.add('hidden'); return; } // Show first 5 emails for preview const previewData = this.processedData.slice(0, 5); previewTableBody.innerHTML = previewData.map(email => ` ${email.from || 'N/A'} ${email.to || 'N/A'} ${email.subject || 'N/A'} ${email.date || 'N/A'} ${email.messageId || 'N/A'} ${email.bodyPreview || 'N/A'} `).join(''); previewSection.classList.remove('hidden'); } hidePreview() { document.getElementById('previewSection').classList.add('hidden'); } downloadResult() { if (this.processedData.length === 0) { this.showError('No data to download. Please process EML files first.'); return; } const formatRadio = document.querySelector('input[name="format"]:checked'); const format = formatRadio ? formatRadio.value : 'csv'; try { if (format === 'excel') { this.downloadAsExcel(); } else { this.downloadAsCSV(); } } catch (error) { this.showError('Error creating download file: ' + error.message); console.error('Download error:', error); } } downloadAsExcel() { const wb = XLSX.utils.book_new(); const wsData = [ ['Filename', 'From', 'To', 'CC', 'BCC', 'Subject', 'Date', 'Message ID', 'Content Type', 'X-Mailer', 'Return Path', 'MIME Version', 'File Size', 'Body Content'] ]; this.processedData.forEach(email => { wsData.push([ email.filename || '', email.from || '', email.to || '', email.cc || '', email.bcc || '', email.subject || '', email.date || '', email.messageId || '', email.contentType || '', email.xMailer || '', email.returnPath || '', email.mimeVersion || '', email.fileSize || '', email.body || '' ]); }); const ws = XLSX.utils.aoa_to_sheet(wsData); // Auto-fit column widths const colWidths = wsData[0].map((_, colIndex) => { const maxLength = Math.max( ...wsData.map(row => String(row[colIndex] || '').length) ); return { wch: Math.min(Math.max(maxLength, 10), 50) }; }); ws['!cols'] = colWidths; XLSX.utils.book_append_sheet(wb, ws, 'Email Data'); const timestamp = new Date().toISOString().slice(0, 19).replace(/[:-]/g, ''); const filename = `eml-converted-${timestamp}.xlsx`; XLSX.writeFile(wb, filename); this.showSuccess(`Excel file "${filename}" downloaded successfully! Contains ${this.processedData.length} email records.`); } downloadAsCSV() { const csvContent = this.convertToCSV(); const blob = new Blob(['\uFEFF' + csvContent], { type: 'text/csv;charset=utf-8;' }); const link = document.createElement('a'); const url = URL.createObjectURL(blob); link.setAttribute('href', url); const timestamp = new Date().toISOString().slice(0, 19).replace(/[:-]/g, ''); const filename = `eml-converted-${timestamp}.csv`; link.setAttribute('download', filename); document.body.appendChild(link); link.click(); document.body.removeChild(link); URL.revokeObjectURL(url); this.showSuccess(`CSV file "${filename}" downloaded successfully! Contains ${this.processedData.length} email records.`); } convertToCSV() { const headers = ['Filename', 'From', 'To', 'CC', 'BCC', 'Subject', 'Date', 'Message ID', 'Content Type', 'X-Mailer', 'Return Path', 'MIME Version', 'File Size', 'Body Content']; const rows = this.processedData.map(email => [ email.filename || '', email.from || '', email.to || '', email.cc || '', email.bcc || '', email.subject || '', email.date || '', email.messageId || '', email.contentType || '', email.xMailer || '', email.returnPath || '', email.mimeVersion || '', email.fileSize || '', email.body || '' ]); const csvRows = [headers, ...rows].map(row => row.map(field => { const fieldStr = String(field || '').replace(/"/g, '""'); return `"${fieldStr}"`; }).join(',') ); return csvRows.join('\n'); } clearAll() { this.files = []; this.processedData = []; this.updateFileList(); this.updateButtons(); this.hidePreview(); document.getElementById('downloadButton').disabled = true; document.getElementById('fileInput').value = ''; // Clear any existing messages const messages = document.querySelectorAll('.error-message, .success-message, .info-message'); messages.forEach(msg => msg.remove()); this.showSuccess('All files cleared successfully.'); } formatFileSize(bytes) { if (bytes === 0) return '0 Bytes'; const k = 1024; const sizes = ['Bytes', 'KB', 'MB', 'GB']; const i = Math.floor(Math.log(bytes) / Math.log(k)); return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i]; } showError(message) { this.showMessage(message, 'error'); } showSuccess(message) { this.showMessage(message, 'success'); } showMessage(message, type) { // Remove existing messages of the same type const existingMessages = document.querySelectorAll(`.${type}-message`); existingMessages.forEach(msg => msg.remove()); const messageDiv = document.createElement('div'); messageDiv.className = `${type}-message`; messageDiv.innerHTML = `

${type === 'error' ? 'error' : type === 'success' ? 'check_circle' : 'info'} ${message}

`; const container = document.querySelector('.eml-converter-container'); const header = container.querySelector('.header'); container.insertBefore(messageDiv, header.nextSibling); // Auto-remove after 8 seconds setTimeout(() => { if (messageDiv.parentNode) { messageDiv.remove(); } }, 8000); } } // Initialize the converter when the page loads let emlConverter; document.addEventListener('DOMContentLoaded', () => { emlConverter = new EMLConverter(); });

EML to Excel/CSV Converter – Professional Email Processing Tool

What is an EML File?

EML (Electronic Mail) is a standard file format used to store individual email messages. The format was originally developed by Microsoft for Outlook Express but has become an industry standard supported by virtually all email clients. EML files contain the complete email structure including:

• Email Headers: From, To, CC, BCC, Subject, Date, Message-ID
• Message Body: Plain text and/or HTML content
• Attachments: Files attached to the email (encoded within the file)
• Metadata: MIME information, routing details, and technical headers

EML files preserve the exact format and content of emails, making them ideal for email archiving, forensic analysis, legal documentation, and data migration between email systems.

About This Conversion Tool

This EML to Excel/CSV Converter is a professional-grade, client-side web application designed to extract and convert email data from EML files into structured spreadsheet formats. Unlike many online converters that upload your sensitive email data to external servers, this tool processes everything locally in your browser for maximum privacy and security.

Key Features

🔄 Batch Processing

• Convert multiple EML files simultaneously
• Progress tracking with real-time status updates
• Handles large volumes of emails efficiently
• Individual file error handling without stopping the entire process

📊 Dual Output Formats

• Excel (.xlsx): Professional spreadsheet format with auto-fitted columns
• CSV: Universal format compatible with databases, analytics tools, and spreadsheet applications
• UTF-8 encoding with BOM for proper international character support

👀 Data Preview

• Preview extracted email data before download
• Verify data accuracy and completeness
• Shows first 5 emails in a formatted table
• Full data preservation without modification

🎨 Material 3 UI Design

• Modern, responsive interface using Google’s Material Design 3
• Custom green theme (#0ac16c) for professional appearance
• WordPress-compatible with isolated styling
• Mobile-friendly responsive layout

🔒 Privacy & Security

• 100% client-side processing – no data leaves your browser
• No server uploads or external API calls
• Secure file handling with proper error management
• Complete data integrity preservation

Technical Specifications

Data Extraction Capabilities

• From/To/CC/BCC: Complete recipient information
• Subject: Email subject lines with encoding support
• Date/Time: Original send timestamps
• Message ID: Unique email identifiers
• Content Type: MIME type information
• X-Mailer: Sending application details
• Return Path: Email routing information
• MIME Version: Email format version
• Body Content: Full message text with HTML-to-text conversion
• File Metadata: Original filename and file size

Advanced Processing Features

• RFC 2047 encoded-word decoding (handles international characters)
• Quoted-printable content decoding
• HTML-to-plain-text conversion with tag removal
• Header continuation line processing
• Duplicate file detection and handling
• Comprehensive error handling and validation

How to Use the Tool

Step 1: Upload EML Files

• Drag & Drop: Simply drag EML files onto the upload area
• Browse: Click “Browse Files” to select files from your device
• Batch Upload: Select multiple files at once (Ctrl+Click or Cmd+Click)

Step 2: Review File List

• View all selected files with names and sizes
• Remove individual files if needed using the delete button
• Add more files by repeating the upload process

Step 3: Choose Output Format

• CSV: For database imports, analytics, or simple spreadsheet use
• Excel: For professional reports, advanced formatting, or Microsoft Office compatibility

Step 4: Process Files

• Click “Process Files” to begin conversion
• Monitor progress with the real-time progress bar
• View processing status for each file

Step 5: Preview & Download

• Review extracted data in the preview table
• Verify data accuracy and completeness
• Click “Download Result” to save your converted file

How to Open EML Files on Different Platforms

🪟 Windows

• Microsoft Outlook: Native support, double-click to open
• Windows Mail: Built-in Windows 10/11 email client
• Mozilla Thunderbird: Free, cross-platform email client
• Web Browser Trick: Rename file to .mht extension and open in any browser
• Text Editor: View raw email source in Notepad++ or similar

🍎 macOS

• Apple Mail: Default email client with native EML support
• Microsoft Outlook for Mac: Full compatibility with EML format
• Mozilla Thunderbird: Cross-platform solution
• Text Editors: TextEdit, Sublime Text, or VS Code for raw viewing
• Quick Look: Preview files directly in Finder

🐧 Linux

• Mozilla Thunderbird: Most popular choice for Linux users
• Evolution: GNOME’s default email client
• KMail: KDE’s integrated email solution
• Claws Mail: Lightweight, fast email client
• Command Line: cat, less, or vim for text-based viewing

📱 Android

• Letter Opener: Dedicated EML viewer app from Google Play
• EML Reader: Specialized apps for mobile EML viewing
• Email Clients: K-9 Mail, FairEmail, or other IMAP clients
• File Managers: Some advanced file managers can display EML content
• Text Viewers: For viewing raw email source

Use Cases & Applications

📧 Email Migration

• Moving emails between different email systems
• Converting archived emails to spreadsheet format
• Bulk email data analysis and reporting

⚖️ Legal & Compliance

• eDiscovery processes for legal proceedings
• Compliance auditing and documentation
• Forensic email analysis for investigations

📊 Data Analysis

• Email communication pattern analysis
• Customer correspondence tracking
• Marketing email performance measurement

🏢 Business Applications

• Customer service email archiving
• Lead tracking from email inquiries
• Communication audit trails

🔬 Research & Analytics

• Academic research on email communication
• Social network analysis from email data
• Language and sentiment analysis

Technical Requirements

• Browser: Modern web browser with JavaScript enabled
• File Types: .eml files (Electronic Mail format)
• File Size: No strict limits (processed in browser memory)
• Internet: Required only for initial page load (no ongoing connection needed)

Privacy & Data Security

This tool is designed with privacy as the top priority:

• No Server Processing: All conversion happens in your browser
• No Data Transmission: Your emails never leave your device
• No Storage: Tool doesn’t save or cache any email content
• No Analytics: No tracking or monitoring of your email data
• Open Source Compatible: Code can be self-hosted for maximum security

Advantages Over Alternative Solutions

vs. Online Converters

• ✅ No privacy risks from uploading sensitive emails
• ✅ No file size or quantity limitations
• ✅ No internet dependency after initial load

vs. Desktop Software

• ✅ No installation required
• ✅ Cross-platform compatibility
• ✅ Always up-to-date
• ✅ No software licensing costs

vs. Email Client Exports

• ✅ Direct EML file processing
• ✅ Batch processing capabilities
• ✅ Standardized output format
• ✅ Preserved original email structure

This EML to Excel/CSV Converter represents the perfect balance of functionality, security, and ease-of-use for anyone needing to convert email files into structured data formats. Whether you’re handling a few emails or processing thousands of archived messages, this tool provides the professional capabilities you need while maintaining the highest standards of data privacy and security.