Seems these webmail softwares use the wrong message ID to refer to the
mailbox mail !!
Seems they use the LIST command result to 'point' to the messages in the
mailbox and it is a BAD practice :
 LIST command returned values are not guaranteed to preserve message IDs
across sessions
So LIST command is generally used for pop3 client that will retreive all the
mail, just using the LIST command to have an 'idea' of the number of mail
available at the time of the list command

To point to specific mails in the mailbox, programs (webmail or mua) MUST
use the UIDL command to get real 'pointers' to the mails in the mailbox !!
The UIDL are 'guaranteed' to point to the same mail in the mailbox and are
not subject to change across sessions

To clarify : On POP3 protocol, you have two commands to get the list of
mails present in the mailbox : LIST or UIDL

LIST
+OK 5 15000
1 5034
2 2552
3 1195
4 1555
5 4664

So when a new mail comes in, in next LIST you can have :
LIST
+OK 6 15255
1 2552
2 4664
3 255
4 1195
5 1555
6 5034

And the webmail asking to delete message 3 (1195 bytes from first list
command reference) will effectively delete message 3 (255 bytes) if delete
command is send after new message is received in mailbox

The GOOD webmail should USE the UIDL command :

UIDL
+OK 4
1 1028745715263.1556.toto
2 1062432866368.1924.toto
3 1062433302173.1404.toto
4 1067127927549.1956.toto

The uidl is the right walue (1028745715263.1556.toto for example) and will
not change after deleting messages or receiving new messages.
The first colomn is only a counter, not a 'pointer'/index (just to count the
number of returned lines)
So after the server receive a new mail the UIDL will return something like
this :

UIDL
+OK 4
1 1028745715263.1556.toto
2 1062433302173.1404.toto
3 1065447858963.2556.toto (new mail here)
4 1067127927549.1956.toto
5 1062432866368.1924.toto

Even if the returned lines order can change (so don't use the first value as
the index), the uidl don't change and point to the original good message !!!


Francis




> -----Message d'origine-----
> De : Dan Porter [mailto:[EMAIL PROTECTED]
> Envoyé : jeudi 16 juin 2005 09:35
> À : [email protected]
> Objet : [xmail] Problem with XMail, POP and all Webmail Software
> 
> 
> 
> I have discovered a problem when using Xmail with POP and Webmail.
> 
> I have had this problem using different webmail software, including:
> -Horde
> -Ilohamail
> -umpl_xmail
> -dwmail
> 
> Since the problem occurs in so many different types of 
> software, it may 
> be something with Xmail, and it may be something with POP.
> 
> The Problem: When you click to view an email, from your 
> webmail inbox, 
> the wrong email is shown. When you click to delete an email, 
> from your 
> webmail inbox, the wrong email is deleted.
> 
> How to generate the problem:
> -Have a few emails in your inbox, log into your webmail and list out 
> your inbox.
> -From another window, or Outlook, or somewhere else, send 
> yourself an email.
> -Wait a minute or so to let your server process the email.
> -Click on an email in your inbox. If the wrong email shows 
> up, you have 
> created the same error as me.
> OR, delete an email in your inbox. If the wrong email is deleted you 
> have experienced the same problem.
> 
> What causes the problem:
> It seems like an index problem. Lets say you have three 
> emails in your 
> inbox. Each email will have a link on it so that you can click in to 
> view that email, something like this:
> My Inbox
> view.php?id=1 Email From Bob
> view.php?id=2 Email From Mary
> view.php?id=3 Email From Ted
> 
> Now pretend that as you are viewing your inbox, Jill sends 
> you an email. 
> Before you refresh your inbox, you decide to click on the Email From 
> Mary to view it.
> 
> Instead, you will be seeing the email from Bob. How come? 
> It's because 
> the indexes have shifted. If you go back to your inbox, it will be 
> something like this:
> My Inbox
> view.php?id=1 Email From Jill
> view.php?id=2 Email From Bob
> view.php?id=3 Email From Mary
> view.php?id=4 Email From Ted
> 
> Now you see why clicking on the email with an index of 2 brought up 
> Bob's email rather than Mary's. This is a way oversimplified 
> version of 
> the problem, as the indexes are generally not in order (but 
> they can be).
> 
> 
> 
> Has anyone else noticed anything similar, or am I alone out 
> there? Any 
> suggestions?  I don't really want to go to IMAP, too 
> intensive on resources.
> -
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