Odd Mailbox behaviour

[baxlobs]

I have 2 e-mail accounts set up in Apple Mail.

I have added some extra Mailboxes in one account so that I can sort the important messages that I want to keep.

At first these seemed to work OK, but in the last few days they just vanish in an apparently random fashion when waking the iMac.

I can get them back by Synchronising All, but all the messages have to be downloaded again from the server. This is moderately annoying.

Is there an explanation, and what can I do to prevent this odd behaviour?

 

[baxlobs]

Bump,

Does anyone have any ideas?

It is alright for a day or two then loses the mailboxes again and all the messages have to be re-loaded.

It happened yesterday when I was using the Mac, not just when waking. I saw the mailboxes just vanish.