Release Notes

Papercut SMTP v7.5.0 [2025-10-28]

New Features

• Search Functionality - Added Ctrl+F search to all message detail views (Message, Body, Headers, and Raw). Fixes #295
• Zoom Controls - Added Ctrl+Mouse Scroll Wheel zoom support to message detail views with persistence and visual indicators. Fixes #323
• Attachment Display - Attachments now display in the main message panel with icons and easy access. Fixes #112
• Context Menu for Links - Right-click context menu added for email links with copy and open functionality. Fixes #218
• Empty State Placeholders - Added smart empty state messaging to message list and detail views for better first-time user experience. Fixes #268
• SMTP Authentication and TLS/STARTTLS Support - Full support for SMTP authentication and TLS/STARTTLS encryption for secure email testing. Fixes #102
• Periodic Background Rules - Added periodic background rule execution with mail retention cleanup to both UI and Service. Related to #251
• Windows Package Manager (winget) Support - Papercut SMTP can now be installed and updated via winget. Fixes #231
• File Links Support - Made file:/// links functional by opening with shell/explorer. Fixes #232
• Example Console Applications - Added comprehensive example console applications for email testing scenarios
• Installer Help Support - Added help parameter support for PowerShell/cmd users. Fixes #287

Improvements

• Word-Wrap Support - Added CSS word-wrap support to HTML email rendering for better display of long text strings. Fixes #154
• Non-Standard Email Domains - Added support for non-standard email domains in development environments (e.g., .local, .dev). Fixes #284
• SSL Certificate Error Handling - Added optional SSL certificate error handling for WebView2 to support self-signed certificates. Fixes #243
• Comprehensive Unit Tests - Added extensive unit tests with FluentAssertions for improved code quality and reliability
• NuGet Package Upgrades - Upgraded all NuGet packages to latest versions, including migration to new Polly ResiliencePipeline API
• Service Architecture - Refactored attachment and process handling into dedicated services for better separation of concerns
• Settings Debouncing - Implemented debounced settings saves using Rx Throttle operator to reduce unnecessary I/O

Bug Fixes

• Window Size Saving - Fixed window size not saving correctly when minimized. Fixes #327
• PDF Attachment Opening - Fixed PDF attachment opening on Windows 11 24H2 and double-click issues. Fixes #310, #280
• Message Rendering with # Characters - Fixed message rendering for subjects containing # characters. Fixes #282 (Thanks, xavero!)
• SMTP IP Logging - Fixed SMTP service not logging remote client IP address correctly. Fixes #291
• Empty State Flicker - Fixed placeholder flicker when switching between emails
• WebView2 Deserialization - Added robust error handling for WebView2 message deserialization
• Null Safety - Various null safety improvements and fixes throughout the codebase
• Process.Start Null Checks - Added null checks for Process.Start return values to prevent exceptions

Code Quality

• Refactored to use IUiCommandHub.ShowMessage instead of MessageBox.Show for better testability
• Extracted debouncing logic into reusable SettingsSaveDebouncer
• Improved async patterns and error handling in example applications
• Fixed test assertions to use FluentAssertions consistently
• Added nullable reference type attributes throughout codebase

Documentation

• Added comprehensive TLS/STARTTLS setup documentation with Docker examples
• Created example projects: SendEmailTest, SendRichEmailTest, SendWordWrapTest, SendEmailWithTls, SendEmailWithFileLinks
• Improved Docker documentation with troubleshooting guides
• Added installation guide for PowerShell and command-line users

Contributors

Special thanks to xavero for fixing message rendering with # characters!

Upgrading

NOTE: Velopack "Auto-Upgrade" doesn't work before this (v7.0.2) version. You must download the setup and re-run it to upgrade. Once you're on this version, the auto-upgrade system will work!