old summery lines on IMAP group

[Torsten Mueller]

I have several Gnuses on different machines. I have the same IMAP
groups on all of them. If I go into one group Gnus gets the summary
informations from the IMAP server an stores them into a local file
called .overview located in the agent directory. But I don't have my
IMAP groups in the agent. The server buffer shows not a single server
chached by the agent.

Now, if I delete a mail using Gnus (or the web frontend of my mail
provider or any other news reader) the stored summary information on
the other machines gets obsolete. The mail doesn't exist anymore on
the server but the summary line remains visible in the summary buffer.
If I press RET on this line I get a "No such article (may have expired
or been cancelled)" message.

But what then? How can I delete an obsolete summary line without
editing the .overview file? Is there a command in Gnus like "make the
summary buffer forget all it's local stuff and show the current
situation on the IMAP server"?

T.M.