refern. VS StackMail

• Infinite Canvas
  Arrange references on an infinite spatial canvas with layers, text, and groups.
• Canvas Drawing & Shapes
  Freehand pen with pressure, eraser, 9 shape tools, and color swatches.
• In-App Image Cropping
  Crop images in place or save as a new copy, with crop provenance tracked.
• Image Filters
  Adjust brightness, contrast, saturation, and hue on images and canvas elements.
• Never Copies Your Files
  References images from your own folders. No proprietary library, no doubled disk.
• Relationship Graph View
  Navigate your library as a graph of folders, tags, canvases, and linked images.
• Visual Similarity Search
  Find similar images locally with a built-in feature vector. No uploads, no API cost.
• Color Search
  Search your library by hex code or dominant color with fast local scoring.
• Operator Search
  Full-text search with 16 inline operators like type:, tag:, rating:>=3, and color:.
• Hierarchical Tags
  Parent-child hierarchies, tag groups, linked tags, and macros for bulk tagging.
• Smart Folders
  Saved multi-condition searches that stay up to date automatically.
• Image Grouping
  Stack related references into groups shown as fan cards in the grid.
• Cross-References & Backlinks
  Link any asset to any other and see backlinks across folders and canvases.
• Grid Layout Modes
  Masonry, justified, and horizontal layouts, set globally or per folder.
• Duplicate Detection
  Find duplicate images by perceptual hash with an is:duplicate query.
• Metadata Management
  Rating, color labels, description, notes, source URL, creator, and custom fields.
• Directory Metadata Presets
  Auto-apply tags and metadata when files are added to a folder.
• EXIF / IPTC / XMP Import
  Read embedded tags and ratings from images for DAM interoperability.
• Import Staging
  Drag, drop, or paste images into a staging area with metadata pre-fill and dedup.
• Browser Extension
  Save images from the web with hover buttons and batch save (Chrome, Firefox, Safari).
• Eagle Import
  Migrate an existing Eagle library into refern.
• Disk Sync
  Detect external file changes and reconcile your library with what is on disk.
• Timed Study Mode
  Full-screen reference practice sessions with configurable duration and count.
• Pin Window On Top
  Always-on-top mode keeps references visible while you work.
• Window Transparency
  Adjustable window opacity for overlay reference.
• Click-Through Mode
  Interact with apps beneath the transparent window.
• Desktop Screenshot Tool
  Capture your screen directly into your library.
• Scales to Millions of Images
  Streaming indexer handles 2M+ file libraries with bounded memory.
• RAW & HEIC Support
  Decodes camera RAW, HEIC, SVG, and standard image formats into thumbnails.
• Directory Customization
  Custom folder icons, cover images, and backgrounds in the tree and grid.
• Local-First & Private
  Works fully offline. No account, no telemetry. Files stay on your disk.

• Privacy-Focused
  StackMail emphasizes data privacy and security, offering encrypted email services without scanning user data for advertising purposes, appealing to privacy-conscious businesses.
• Business-Oriented Features
  Designed specifically for businesses, it includes features like custom domain email, collaborative tools, calendars, and contact management tailored for professional use.
• Competitive Pricing
  StackMail offers competitively priced plans compared to some larger email providers, making it accessible for small to medium-sized businesses.
• No Ads
  Unlike some free email services, StackMail does not display ads to users, providing a cleaner and more professional email experience.
• Custom Domain Support
  Users can easily set up email addresses with their own custom domain names, enhancing brand professionalism and consistency.

Possible disadvantages

• Limited Brand Recognition
  As a newer or lesser-known provider compared to Google Workspace or Microsoft 365, StackMail may lack the trust and reputation that larger providers have established.
• Fewer Third-Party Integrations
  Compared to major email service providers, StackMail may offer fewer integrations with third-party apps and services, limiting its versatility for some businesses.
• Limited Advanced Features
  It may not offer the same breadth of advanced productivity and collaboration tools that come bundled with larger platforms like Microsoft 365 or Google Workspace.
• Smaller User Community
  Due to a smaller user base, there may be fewer community resources, third-party tutorials, or troubleshooting forums available online.
• Uncertain Long-Term Support
  As a smaller company, there might be concerns regarding the long-term viability, updates, and continued support of the service compared to more established providers.