6.8.8 Agent and IMAP

The Agent works with any Gnus back end, including nnimap. However, since there are some conceptual differences between NNTP and IMAP, this section (should) provide you with some information to make Gnus Agent work smoother as a IMAP Disconnected Mode client.

The first thing to keep in mind is that all flags (read, ticked, etc) are kept on the IMAP server, rather than in `.newsrc' as is the case for nntp. Thus Gnus need to remember flag changes when disconnected, and synchronize these flags when you plug back in.

Gnus keeps track of flag changes when reading nnimap groups under the Agent. When you plug back in, Gnus will check if you have any changed any flags and ask if you wish to synchronize these with the server. The behavior is customizable by gnus-agent-synchronize-flags.

If gnus-agent-synchronize-flags is nil, the Agent will never automatically synchronize flags. If it is ask, which is the default, the Agent will check if you made any changes and if so ask if you wish to synchronize these when you re-connect. If it has any other value, all flags will be synchronized automatically.

If you do not wish to synchronize flags automatically when you re-connect, you can do it manually with the gnus-agent-synchronize-flags command that is bound to J Y in the group buffer.

Some things are currently not implemented in the Agent that you'd might expect from a disconnected IMAP client, including:

• Copying/moving articles into nnimap groups when unplugged.

• Creating/deleting nnimap groups when unplugged.

Technical note: the synchronization algorithm does not work by "pushing" all local flags to the server, but rather incrementally update the server view of flags by changing only those flags that were changed by the user. Thus, if you set one flag on an article, quit the group and re-select the group and remove the flag; the flag will be set and removed from the server when you "synchronize". The queued flag operations can be found in the per-server flags file in the Agent directory. It's emptied when you synchronize flags.