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 also 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 at the server to avoid downloading huge attachments or spam. You can search through virtual folders that automatically collect all messages matching certain criteria. 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 makes 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 emails into safe and simple text. The rendering is neat and reasonably secure. It also colorizes quoted text and sorts messages by 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. Supports 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, and Unix. It requires KDE.
Composing Emails With KMail
The message editor supports HTML formatting as well as powerful plain text editing. You can configure the templates used to generate new messages and replies, and set up additional templates for quick replies. You can use this setup to change, for example, how the first email in a thread is copied.
KMail also allows you to set up text shortcuts that automatically expand to longer and often-used phrases. If you insert images in emails, KMail can shrink images 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.