An email client that functions like a kanban board, for Mac/Windows/Linux/Docker. Download the latest release here.
- Works on MacOS (beta), Linux (alpha) & Windows (alpha)
- Developed using Gmail, Outlook & Fastmail
- Should be compatible with other email providers (uses IMAP/SMTP)
- Considered in "beta" - used as primary email client for >1yr
The rest of this readme focuses on the technical details of Kanmail. For user documentation see the docs directory.
License
Before continuing it is important to note that Kanmail is source available but not free. Kanmail is available for free download for evaluation; for continued use of Kanmail a license should be purchased.
We welcome pull requests, but note you will be contributing to a non-free project. You will be required to sign the Oxygem CLA before any contributions can be merged. We offer free license keys to contributors, please email hello@oxygem.com for more information.
Development
Setup your system
MacOS
Python must be configured --with-framework. See this StackOverflow answer to check whether this is enabled.
To build/release you'll need to intsall GNU tar, which can be done with brew:
brew install gnu-tar
Linux (Ubuntu)
For qt to install properly you'll need:
apt install build-essential pkg-config git python3-dev libcairo2-dev libgirepository1.0-dev
Then, after requirements are installed you need to edit this pyinstaller file and comment out the lines that add fontconfig/icons/themes (prevents the resultant bundle being >200mb).
Windows
You'll need the Visual Studio build tools.
Install requirements
Python
Kanmail requires Python 3.7. Install the Python requirements with pip:
# Generic development requirements
pip install -r requirements/development.txt
# Platform specific requirements
pip install -r requirements/[macos, linux, windows].txt
JavaScript
Install the JavaScript requirements with yarn:
yarn
Start the app
Run as a server
To start the server + webpack-server:
honcho start
Then go to http://localhost:4420 to view/develop the app in a browser of your choice.
Run as an app
To start the full windowed app, use:
honcho start -f Procfile-app
Note that the webserver does not auto-reload when running in app mode.
Releases
Version numbers are generated at build in the date-based format: MAJOR.YYMMDDhhmm.
Building
Per the pyinstaller documentation, for maximum compatability Kanmail is ideally built on the oldest systems available. MacOS + Linux builds are forward, but not backward, compatible.
Kanmail is currently built on:
- MacOS 10.15 (using 10.12 SDK), compatible with 10.12+
- Ubuntu 18 64 bit, compatible with libc6 2.27+
- Windows 10 64 bit, compatible with ?
Build environments
MacOS
Should use the oldest SDK possible. Kanmail will be compatible with the SDK version of any newer versions, but nothing older, so target the oldest realistic SDK, which is currently 10.12 / Sierra. Heavily based on this gist.
- Use xcodelegacy to download old OSX SDK files
Setup a separate environment
export BUILD_ENV_PREFIX=/opt/osx10.12-env
export PATH="$BUILD_ENV_PREFIX/Frameworks/Python.framework/Versions/3.7/bin:$BUILD_ENV_PREFIX/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin"
export MACOSXSDK=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk
export MACOSX_DEPLOYMENT_TARGET="10.12"
export CFLAGS="-isysroot $MACOSXSDK -I$MACOSXSDK/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -I$BUILD_ENV_PREFIX/include "
export LDFLAGS="-isysroot $MACOSXSDK -L$BUILD_ENV_PREFIX/lib "
export LD_LIBRARY_PATH="$BUILD_ENV_PREFIX/lib/"
export CXXFLAGS="-isysroot $MACOSXSDK -I$BUILD_ENV_PREFIX/include "
export CPPFLAGS="-I$MACOSXSDK/usr/include -I$BUILD_ENV_PREFIX/include -I$BUILD_ENV_PREFIX/include/openssl "
OpenSSL
Download & untar openssl-1.0.2u.
./Configure --prefix=$BUILD_ENV_PREFIX \
no-hw no-hw-xxx no-ssl2 no-ssl3 no-zlib zlib-dynamic \
shared enable-cms darwin64-x86_64-cc enable-ec_nistp_64_gcc_128 \
-isysroot$MACOSXSDK \
-mmacosx-version-min=$MACOSX_DEPLOYMENT_TARGET
make depend
make
make install
Python
Download & untar Python-3.7.6.
./configure --prefix=$BUILD_ENV_PREFIX/ \
--enable-ipv6 \
--enable-framework=$BUILD_ENV_PREFIX/Frameworks/ \
--with-openssl=$BUILD_ENV_PREFIX \
MACOSX_DEPLOYMENT_TARGET="$MACOSX_DEPLOYMENT_TARGET"
make
make install PYTHONAPPSDIR=$BUILD_ENV_PREFIX/Applications
# Tidy up
cd $BUILD_ENV_PREFIX/Frameworks/Python.framework/Versions/3.7/bin
ln -s python3 python
ln -s pip3 pip
Finally install the requirements (from source, no binaries):
pip install pip -U
pip install -r requirements/macos.txt
Using this environment should now build apps compatible with MacOS 10.12+. This can be tested by installing a MacOS 10.13 VM.
Linux (Ubuntu)
Should use the oldest libc possible. Currently building using Ubuntu 18 which has libc6 2.27, which is pretty recent.
TBC instructions to build on an older libc.
Windows
Currently builds on Windows 10. Unsure if compatible with previous versions.
Doing a build
Building Kanmail should be as simple as running python -m make.
? Syncing
Kanmail syncs email using the IMAP protocol. Instead of implementing a "complete sync engine" (one which attempts to keep a local copy of the server data), Kanmail uses a cache and loads data on demand. This simplifies the implementation but makes it hard/impossible to behave as an offline email client.
Kanmail keeps in sync with the remote server by checking UID lists. These are cached locally and every "sync" the full list is refreshed, ensuring the local copy is up to date with the server UID list. Email headers are cached against their UIDs.
Currently no actual full email data is cached, only the headers. Meaning when offline Kanmail will load any cached threads into the column view, but it won't be able to open any of these threads.
Initial load (get emails)
When Kanmail starts, the UI attempts to get emails for each folder (both columns and "core" folders like archive/drafts) - this API endpoint is always expected to return a valid response, even if empty, and does not require connectivity. If there is a local cache of UIDs and email headers, these will be returned.
Subsequent calls to this API endpoint will load more emails, loading headers from the server as required.
Updates (sync emails)
During the lifetime of a running Kanmail app it will periodically request to sync emails with the server. At this time the full UID list is reloaded from the server (failing if offline) and any new email headers are fetched. This endpoint returns new emails and the UIDs of any deleted emails from the UID list.