So sometimes I download stuff from my macbook instead of downloading on the raspberry pi, and in that case I transfer files from my macbook using rsync a really handy utility that comes bundled .
just run rsync with source and target flag in addition to the following flags .
rsync -rv -h -t -P -o pi --bwlimit=1000 local/source/directory/or/file email@example.com:/path/on/remote/directory/
my favourite flag in above is -P which will give you progress of the transfer and an estimate time. and second favourite is --bwlimit which is handy if you do not want to choke up the network.
Another utility I would like to talk about here is iperf
iperf is used for measuring the LAN bandwidth, on the server side you can run iperf -s and on the client side run the command iperf -c server-IP -d and it will dump the file transfer rate supported.