Google Message Continuity User Guide - Manual (Page 5)

Mailing Lists
Mailing list support can be turned on by the administrator. Instructions for the administrator are provided in
the Google Message Continuity Administration Guide. Once the mailing lists have been set up on the Gmail
side, email sent to mailing lists from Gmail (when the Exchange server is down) will be correctly delivered
to the correct recipients and down sync'ed to the user accounts when Exchange server is up. Note that
new mailing lists will not be automatically synchronized with Gmail and will need to be migrated using DSS.
Message Conversations
Suppose a Gmail conversation contains five messages, and on the Exchange side the individual messages
are placed in 5 different folders.
On the Gmail side, the conversation appears to have 5 different labels on it -- corresponding to each of the
5 folders on the Exchange side. This is because labels are applied to messages in Gmail (not
conversations) and a conversation shows up as having a label "foo" if any of the messages in the
conversation has the label "foo". This creates some discrepancy in the folder view on Exchange and the
label view on Gmail, since there will be extra conversations in a Gmail label even though the corresponding
message does not exist in the Exchange folder.
Similarly, a folder that has 100 messages on Exchange, can have only 20 conversations on Gmail, with
each conversation having five messages. While all the messages are present, the view appears very
different from the Exchange view.
Supported Clients
Currently Google supports only Outlook connected to Exchange via MAPI.
Your are free to use IMAP clients such as Thunderbird and Outlook Express. However, they may
sometimes experience unexpected behavior, such as messages not getting trashed in Gmail even though
they are deleted on the client. This happens because the clients may have only marked the message as
deleted, but the changes have not yet been updated on Exchange.