Below is a list of mail clients not sending out threading information. This can be also called the list of mail clients pissing me off.

As I explained in my email guidelines, threading informating is very important to follow a conversation within a group of people. Moreover, sending out threading information is easy to implement so not doing it is beyond me.

This page was last modified on $Date: 2001-08-28 13:00:39 -0700 (Tue, 28 Aug 2001) $.

Hall of shame (in no particular order):

• Some versions/configurations of Microsoft Outlook Express (up to at least version 5.50.4133.2400) - the MacOS version apparently does the right thing though (version 5.02.2022) as well the Microsoft Outlook IMO (e.g. Build 9.0.2416 (9.0.2911.0))
• Pegasus Mail for Windows (up to at least version 3.12b)
• Internet Mail Service (up to at least version 5.5.2653.19)
• Lotus Notes (up to at least version 5.0.5)
• Lotus cc:Mail
• MailCity Service
• Windows Eudora Pro (up to version 3) - apparently fixed in version 4.0
• Hotmail
• Novell GroupWise Internet Agent (up to at least version 5.5.5.1)
• Sun NetMail (up to at least version 2.3)
• Mh-rmail
• Opera (up to at least version 5.12 build 932)
• Microsoft Internet E-mail/MAPI (up to at least version 8.0.0.4211)

Of course this list is incomplete, because I don't try to be exhaustive, and it is not always obvious what client was used to send a particular email.

I am going to try and get the authors to do the right thing.

Below is a short non-exhaustive list of mail clients which behave correctly and that I would recommend:

• Unix: Mutt, Pine
• Windows, MacOS: Eudora
• Unix, Windows, MacOS: Netscape's mail client
• Web client: IMP
• Online free mail system: Yahoo! Mail

Of course, there are other clients that you might like better. If you think that one of them should absolutely be listed here, you can contact me.