• Excellent Palm synchronization (if you use Gnome's pilot tools).
• The Evolution PIM suite is excellent, full-featured, and worthy of use.

• Has a vast number of features to enable combing through huge volumes of email in a short time.
• Supports Usenet natively through the same interface, so mailing lists and newsgroups can be combined in logical groups and handled identically.
• Works identically in graphical and text mode, so is well-suited for remote use over a slow connection.

• The preferred address book, BBDB, seems to be somewhat lacking. I've heard rumor that it can be made to connect to LDAP directories, but I've never been able to make it do so.
• Configuration is quite complex.

Impressions

KMail/Kontact

Pros

• Excellent editing abilities. If you don't like the built-in editor, you can configure it to use the external editor of your choice.
• Excellent PGP support.
• No hierarchical group settings, but individual folders are otherwise very flexible. You can define expiration timeouts, default sending account, mailing list information, and other options on a per-folder basis.
• It's full of small but useful niceties that no other program seems to have thought of. For example, if you're sending a message with the the words "attachment" or "attached" (or other entries in a configurable list), but haven't attached a file to your message, the KMail will warn you that you might've forgotten an attachment when you try to send the email.
• Excellent Palm synchronization (if you use KDE's pilot tools).
• The Kontact PIM suite is excellent, full-featured, and worthy of use.

Cons

• LDAP support is severely lacking when compared to Evolution. You can search one or more LDAP directories, and can copy entries from an LDAP directory into your personal address book, but cannot edit entries or copy from your personal address book to the LDAP directory.
• No way to hide folders without unread messages.
• No way to hide read messages.
• No IMAP filtering. Really! That's not a typo. You can filter incoming POP messages, but not your IMAP inbox.

Impressions

Thunderbird

Pros

• The message editor is simple, but functional.
• Excellent built-in spam filtering that learns as you use it.
• Has the nice ability to pre-format reply messages to your preference; you may place your signature above or below the text you're replying to, and have it set the cursor at the top or bottom of your message when first starting. Basically, it lets the user decide whether they want to top- or bottom-post by default.
• Good threading and message-hiding abilities.

Cons

• LDAP support is limited to searching; no editing is supported.
• No Palm synchronization.
• Only one email signature can be configured per outgoing account.
• No message expiration.
• Very simplistic filtering abilities compared to other clients.

Impressions

Recommendations

Extremely Geeky Recommendations

Note that much of my review is necessarily subjective; one person's perfect text editor may be another's exercise in futility. Still, I think that my needs are fairly typical of those who spend a lot of time inside email programs and who really need strong client support to process a large amount of information as efficiently as possible.

Features I Look For

General

• Good editing. I will not use a client that doesn't have an excellent built-in editor, or a way to use the external editor of my choice. Full-stop. I sent too much email to bother with a client that makes it difficult to craft well-formatted messages.
• Spam filtering. Clients that don't have built-in spam detection or an easy way to look for spam headers insert by the mailserver (such as SpamAssassin) are useless to me.
• PGP support. I sign almost every message that I send, and want automatic verification of signatures on incoming messages.
• Multiple outgoing accounts. I receive messages to several different email addresses, and I need to be able to quickly select the address that I want my outgoing messages to be from.
• Hierarchical folder settings. If I have a group of folders with nearly identical settings (such as which signature to use, expiration times, etc.), I don't want to have to configuration those settings in each individual folder. I want a way to make a change in one place and have it propigate to associated folders, but with the ability to override that default setting in a particular folder.
• Save my sent mail where I want it to go. Some of my folders are specific to a certain contact or a particular subject (for instance, a work project). When I reply to a message in one of these folders, I want to save my reply in that folder to that I can see an accurate threaded view of its contents.
• Quality of other integrated programs. If the email client is part of a larger application, then the other parts of that application should also be decent. After all, those components will presumably integrate better with each other than with other programs, so if I want to use the email and address book parts, the calender should also be tolerable.

Address Book

I have several hundred contacts. I do not want to remember each one's current preferred email address.

• Store a lot of information about a contact. The address book should be good enough that I can use it as my primary directory. I do not want to maintain one address book for my email program, and another for everything else.
• LDAP support. This is an absolute must. At work, my company publishes employee contact lists via LDAP. At home, I use LDAP as a way to share information with my wife so that records of our family and friends are maintained in one central location.
• Palm synchronization. I want to take my contacts with me and to be able to edit them on my Palm and have the changes reflected the next time I sync it.

Some clients do not have built-in address books, but integrate tightly with standalone programs. In this case, I consider the recommended or most common external program to be part of the email client for my purposes, since I use them together as a unit.

Mailing List Support

I subscribe to many mailing lists and get a ridiculous number of emails per day. Any client I use must support all of the following:

• Threaded display. I want to see at a glance which message a given email is replying to.
• Powerful mail sorting options. Any client should be able to accurately move incoming messages into the appropriate folder.
• Expiration settings to that I can keep the last n days worth of messages for quick searching, but don't have to manually delete very old messages.
• A way to hide read messages. Some active mailing lists generate hundreds of messages per day, and I want to see just my new mail without having to break the threaded display. That is, switching to "sort by received date" is not an acceptable method of finding new mail.
• A way to hide folders without unread messages. My mail is split across 40 or so folders, and I don't want my display cluttered with a lot of folders that don't have new information.

My Findings

In alphabetical order:

Evolution

Evolution has earned its place as a flagship product of the Gnome project. It is so close to meeting my ideals that I could almost adopt it as my full-time client. However, it still has a few show-stoppers that prevent it from meeting my needs.

Pros

• Other clients take note: this is what LDAP support is supposed to be like. I can search, edit, and save contact information in LDAP directories in exactly the same way as in my local address book. If I could get Evolution to sync my Palm's address book with a given LDAP directory (so that my portable list of work-related contacts was always accurate), it would be absolutely perfect.
• Selecting the appropriate From: header is convenient, and automatically selects the associated email signature by default.

Cons

• The editor is somewhat lacking. For example, sometimes when I'm replying to an email where the sender used abnormally wide or narrow margins, I want to reformat their text for the sake of appearance or readability. I have yet to figure out how to get Evolution's editor to do this. There is no way to specify an external editor.
• No hierarchical (or any other) folder settings.
• As a consequence of the above, there are no expiration settings. You can build a filter to delete old messages that match the same expression used to sort messages into a given folder in the first place, but oh, what a hassle.
• No way to hide folders without unread messages.

Impressions

• Evolution really, really wants to be MicrosoftOutlook^?. This may be good for migrating users from Windows to Unix systems, but comes at the expense of making the application feel out of place on non-Windows desktops.
• This is a probably an excellent client for most people, but lacks the features that "power users" really need.

Gnus

Gnus is probably the most popular email client that runs inside the Emacs editor. It is far and away the most extensible client that I know of - if you can write Lisp, you can make Gnus do anything that a computer can be made to do. I'll try to stick to the out-of-the-box feature set, since listing what Gnus can do isn't possible and isn't fair to other clients ("Can be used to control a Mars-bound spacecraft" is technically true, although not useful to the average user).

Pros

• If you like Emacs, then you'll feel at home in Gnus' editor (which is, after all, Emacs).
• Good spam filtering capabilities.
• I think Gnus invented hierarchical folder settings. At least, it does it better than any other client I've ever seen.

Cons

General

• Good editing.
• Spam filtering.
• PGP support.
• Multiple outgoing accounts.
• Hierarchical folder settings.
• Save my sent mail where I want it to go.
• Quality of other integrated programs.

Address Book

• Store a lot of information about a contact.
• LDAP support. This is an absolute must.
• Palm synchronization.

Mailing List Support

• Threaded display.
• Powerful mail sorting options.into the appropriate folder.
• Expiration settingsbut don't have to manually delete very old messages.
• A way to hide read messages.
• A way to hide folders without unread messages.

KMail/Kontact

Mutt

Squirrelmail

Thunderbird

General

• Good editing.
• Spam filtering.
• PGP support.
• Multiple outgoing accounts.
• Hierarchical folder settings.
• Save my sent mail where I want it to go.
• Quality of other integrated programs.

Address Book

• Store a lot of information about a contact.
• LDAP support. This is an absolute must.
• Palm synchronization.

Mailing List Support

• Threaded display.
• Powerful mail sorting options.into the appropriate folder.
• Expiration settingsbut don't have to manually delete very old messages.
• A way to hide read messages.
• A way to hide folders without unread messages.

-- KirkStrauser - 12 Apr 2004