smtplib sendmail problems

[Hank]

Hi, 

I have a function that sends mail but I'm finding the number of
characters in the To: field is limited to ~255 characters. This means
that email is sent to only part of the email list.


#recipients is a list of email addresses, greater than 255 characters
in total

header = "To: " + string.join(recipients, "; ") + "\r\n" \
         "From: " + "testing at test.com\r\n" \
         "Date: " +  time.strftime("%A, %B %d, %Y %I:%M %p",
sendTime)+ "\r\n"
         "X-Mailer: Automated Test \r\n" \
         "Subject: " + subject + "\r\n\r\n" 
text = header + mailText
server = smtplib.SMTP('something.something.com')
result = server.sendmail("testing at test.com", recipients, text)
server.quit()


Any help is greatly appreciated.

Thanks