Which version of ConnectR? I've been told that v4.6 allows for a max of 2MB, but v4.5 is much less. We're on v4.5 and have seen issues with message lengths longer than about 60,000 characters. I'm not sure how this translate to file size. We've also seen issues with a TCP/IP connection where if the source message was too big, ConnectR never even attempted to receive it (nothing in the logs), therefore never returning an ACK and leaving the source system waiting indefinitely.