With Yahoo, any mail sent off the BB will be stored in the sent folder. Does this work with any other provider, hosted email, corporate mail server (exchange/lotus/etc), windows/linux server?

How does this work on Yahoo? Also, does it use imap or pop?

OWA or IMAP accounts will store sent messages. This is done as each individual account will send through the actually mail server as opposed to through BIS's SMTP servers where possible. I think migrated iNotes accounts will do this as well. Not sure though.

If the email account supports IMAP and you have a Sent and Trash folder, email sent on the BB will be stored in the Sent folder. Deleted email from the BB will be stored in the Trash folder. This is only a one-way sync between the BB and the IMAP server.

One of my mail accounts is on a linux box and it does support imap, but none of my sent mail is being stored. Any suggestions?

Are the subfolders Sent and Trash there? The BIS does not create the Sent or Trash folders. So unless they already exist it will not store them.

The folders are there and it is not storing sent mail. How can I get this working?

Be sure the BIS is setup correctly. Click the configured email account then select Advanced in the options of the BIS screen. Be sure it says IMAP.

It seems that in one of the accounts the Trash folder was missing. It seems strange to me that the sent mail was not being stored in Sent folder though. Also, one of thee accounts is POP and the other is set up as IMAP and both are working correctly now.

Does anyone know why I have a virtual folders box with a virtual inbox subfolder? Does this have anything to do with BIS 2.0?

I made a mistake, it is not storing on the POP account and the IMAP account is able to store sent messages even if the Trash folder is not there.

As far as the virtual folders, they're just a feature of Horde.