I've run into this with a number of pop based clients. From what I have seen, the problem comes up on a client IF there was some sort of error that occured the previous time that client ran. For example, the client for some reason disconnected in the middle of downloading a message. There are 100 message on server. The last 10 were not seen by the client yet so it was downloading those. In the middle of message "new-9" or 99, an error occurred. The client now gets confused about what it has and the next time it downloads, it starts over at message 1. It's wrong, but it happens. I would not blame the server unless I had a strong case that it really did recalc all message UIDL.
--Gene "Michael Nguyen" made the following keystrokes: >> Sascha Wuestemann wrote: >> >> >On Sun, Nov 07, 2004 at 11:53:52PM -0500 or thereabouts, Warrick >FitzGerald wrote: > >Hi Warrick and Sascha, > >> >Hi Warrick, >> > >> >seen information is saved at server side for imap and pop3, too. > >[snip] > >> Let's say you have two POP3 clients one set to leave mail on the server >> for a week and one set to leave mail on the server for a day. >> >> If the one that's leaving thing on the server for a week pick's up mail, >> the other is not effected in any way .. and you're messages are not >> marked as seen in any way. Are you sure POP3 has seen state on the server? > >Yes it is...in a way. It's actually "saved" on both. Technically it's only >saved on the client, but it uses to the server to tell what's been >downloaded. The client asks the server to give a "UID" of the messages on >the server. The client then downloads the messages and records what UIDs it >has seen. When the client checks mail again, it requests UIDs again. Any >UID that it hasn't seen, it requests retrieval. > >Here's how you can try it out yourself: > > - Open a command prompt > - Open a telnet session to your mail server on port 110 > - e.g. telnet mail.sascha.fi 110 > - You'll get a POP3 banner. Login as follows: > - user <username> <enter> (this is how your client passes login name) > - pass <password> <enter> (this is how your client passes your password) > - list <enter> (this is how your client gets a list of your messages. >You are returned a message number with a message size.) > - uidl <enter> (this is how your client gets a list of UIDs for each >message. You are returned a message number with UID) > - At this point you can get a message using RETR (e.g. RETR 1 will retrieve >message 1) > - If your client is set to delete messages after retrieval, the client then >deletes using DELE (e.g. DELE 1 will delete message 1) > >[snip] > >Anyway, what this all means is that the new server-side software merely >recalculated all of your users' UIDs, thus making them appear to be new to >your clients. POP3 is very simple compared to IMAP. There is no "seen" >flag. > > >Michael > >--- >Cyrus Home Page: http://asg.web.cmu.edu/cyrus >Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu >List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html > --- Cyrus Home Page: http://asg.web.cmu.edu/cyrus Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
