Yes. Read the FAQ:
Q. I just found a bug in ifmail: when there is only a *.req file in
outb, ifcico won't call the destination node.
A. This is not a bug, this is a feature :-) If you need to poll the node
to get a file, create an empty .flo together with a .req. If you get
thru to the node, but it says that it does not support freqs at the
moment, the .req file stays in the queue (so you don't need to create
it again next time), but the .flo file is deleted (as the session was
successfull), so ifcico does not continiously poll the node (which
would be annoying).
Also, it is always worth looking into the log.