Administrative prohibition error when sending email

[Lad]

I use a new webhosting provider and I can not send an email from my
script.
This is the script that I use to test the connection

#######################
import smtplib,poplib,

#I first login to my POP3 account
M=poplib.POP3('www.mywebh.com')
M.user('MYWeb)
M.pass_('12345')
print M.pass_ #check if you login successfully

#next send a message
fromaddr = "info at mywebh.com"
toaddrs  = "objednavky at sdeznam.cz"
msg="This is a test"
server = smtplib.SMTP('www.ebayworldstuff.com:25')

server.set_debuglevel(1)
server.sendmail(fromaddr, toaddrs, msg)
server.quit()
#########################

It ends with SMTP error 550: Administrative prohibition

Where can be a problem?
Lad.