You can choose to download either the minimalist ZIP file containing the K9 executable only (no installer or uninstaller) or the full installation EXE that will enable you to uninstall the application and all associated files and registry items if you wish to (recommended for first time users).

It does not natively support SSL or secure authentication. It does not support IMAP nor does it support Hotmail, AOL or any other kind of webmail type systems.

K9 is for standard POP3 email accounts only. More importantly it learns to recognize what you consider to be spam. K9 learns from its mistakes and becomes better and better at being able to identify spam. It uses intelligent statistical analysis that can result in extremely high accuracy over time. K9 is an email filtering application that works in conjunction with your regular POP3 email program and automatically classifies incoming emails as spam (junk email) or non-spam without the need for maintaining dozens of rules or constant updates to be downloaded.

K9 mail client