If you're spreading links around please use releases.mozilla.org which
takes advantage of our mirror network. ftp.mozilla.org is a single
machine and our entire community relies on it as the sole source of
nightly test builds. It will quickly get swamped if people are
downloading releases from it.
ftp://releases.mozilla.org/pub/mozilla.org/thunderbird/releases/
I'll keep that in mind, thanks.
Rimas