I just set up a new desktop client for Gmail (Sparrow), and it is showing some older messages as new. I've emailed them, but still waiting for a response.
Is it common for IMAP to get some time stamp data incorrect? Should I blame the desktop client or IMAP? I haven't had this problem using Apple Mail, but my sense is that it isn't totally the clients fault.
A message is considered recent when it has the \RECENT flag:
From the rfc3501
\Recent Message is "recently" arrived in this mailbox. This session is the first session to have been notified about this message; if the session is read-write, subsequent sessions will not see \Recent set for this message. This flag can not be altered by the client. If it is not possible to determine whether or not this session is the first session to be notified about a message, then that message SHOULD be considered recent. If multiple connections have the same mailbox selected simultaneously, it is undefined which of these connections will see newly-arrived messages with \Recent set and which will see it without \Recent set.
So, as long as the client checks the recent flag you should blame IMAP...
I use IMAP w/ getmail, and it keeps ids of all downloaded messages in ~/.getmail.
This strongly suggests messages "newness" is the client's responsiblity, not the server's.
If you're using timestamps, remember that some people have broken date headers and their messages appear to be in the far future.
When I use getmail to read my gmail, and then visit gmail via website, all the messages still show as "new".
