problem with port (550)

we were using your great program "File by mail" and some time ago we found a problem:
at our server root(we think) closed the 550 port!!!! 
But we still want to get files(more than 1Mb) throught your servers
And now we can not send reguests with "File by mail" program  :-(((((
is there any suggesions????? Help us PLEASE!!!!!!!

we are waiting for answer!