Error 1 : Can't create/write to file

[cicciopasticcio]

I'm trying from ssh a SELECT...INTO OUTFILE but I receive the same error Error 1 : Can't create/write to file

mysqldump -uUSER -pPASSWORD --fields-terminated-by='|' --fields-optionally-enclosed-by='"' --lines-terminated-by='\n' --tab=/srv/www/vhosts/mysite/httpdocs/myfolder/ DATABASE TABLE > file.csv

The file is created but written partially.
I've check file permission and they are 0644

So I went in proftpd.conf and I've seen umask 022. I've understood that this is the problem. So I found http://www.castaglia.org/proftpd/do...WTO-Umask.html,
but I REALLY DON'T UNDERSTAND WHAT I HAVE TO DO!!

Please Help me... I'll become crazy...

Thanks,

Luca