A possible explanation would be that you have the account set up as POP (at least on the work PC), and the work PC does not or no longer have the Leave messages on server option checked in its account settings. Does that apply?

Of course you could check the mail server’s content right after fetching email on the work PC, i.e. if it’s gone there, it means it was removed by that client.

Hi. It is set up as an IMAP account and I cannot find an option to leave messages on the server. I do have another account on TB (POP with Yahoo) which does show me that option though under the Server Settings tab. I have changed nothing in the settings on TB for ages but this seems to have started following recent updates????

Hello again. One thing I have just noticed is that the mails I send from home still appear in the Sent folder at work so it seems that it is only a problem for those I receive.

Just been advised by my site administrator that they had issues. All seems to be back as it was now! Many thanks