KMail Review - Free Email Program

Is KMail the right email client for the Linux superuser?

KMail 4.14 screenshot
The KMail Team

With so many different options for email clients, choosing one can be intimidating. While a bit feature-heavy, KMail can offer plenty of control for the email superuser.

KMail is the email component of the KDE Desktop Environment. Reasonably easy to use, powerful, and versatile, it is a mostly solid email client for Linux.

What We Like
  • Powerful and flexible mail filters and virtual folders for email management.

  • Integrates secure, encrypted email using both OpenPGP and S/MIME.

  • Configurable message templates and text expansion help compose replies using oft-used text.

What We Don't Like
  • Variety of options, menu items, and functions can be a bit overwhelming.

  • Lacks internal spam filters or tight integration with external tools.

KMail: The Basics

Like most of KDE, KMail combines powerful features, useful tools, and an easy to use interface. It can manage multiple POP and IMAP accounts, as well as mbox and maildir mailboxes. It even allows multiple identities for sent emails.

KMail features powerful and flexible internal mail filters, as well as support for procmail filtering and Sieve scripts at the server level. The email component can filter mail directly at the server to avoid downloading huge attachments or spam. Users can search through virtual folders that automatically collect all messages matching certain criteria. Oddly, these criteria do not include message tags, which you can set up and apply freely to messages or conversations.

Most users appreciate KMail's fast and powerful search function. The addition of expressions and virtual folders make email management a snap. And with IMAP accounts, you can search folders in addition to searching locally.

KMail supports the display of HTML emails, but can also transform them into safe and simple text. The rendering is both neat and reasonably secure. It also colorizes quoted text and can sort messages by their threads. Unwanted mail can be bounced back to the sender, simulating a dead email address. Also, integration with the calendar lets you easily create to-do items, such as reminders.

A bit more about KMail:

  • Supports OpenPGP/GnuPG cryptography and TLS/SSL connections natively, external plug-ins for S/MIME.
  • Automated archiving backs up entire folders on a schedule to a compressed archiving file.
  • Imports mail and addresses from many email programs.
  • Supports Linux/BSD/Unix and requires KDE.

Composing Emails With KMail

The message editor supports HTML formatting as well as powerful plain text editing. Not only can you fully configure the templates used to generate new messages and replies, you can set up additional templates for quick replies. You can use this setup to change, for example, the way the first email in a thread is copied.

KMail also allows you to set up text shortcuts that automatically expand to longer and oft-used phrases. If you insert images in your emails, KMail can shrink them to an appropriate size for most email services and programs. If this is not enough, an external editor (like vim or Emacs) can be used to edit messages.

All in all, KMail is a worthy contender to the likes of Mozilla Thunderbird or web-based interfaces like Gmail.