Testing on Linux:

$ ulimit -m 128000
$ ulimit -v 196000
$ python test_MIMEText.py
[...]
Traceback (most recent call last):
  File "test_MIMEText.py", line 23, in <module>
    txt = MIMEText(buffer, _subtype="plain", _charset="iso-8859-1")
  File "/usr/lib/python2.5/email/mime/text.py", line 30, in __init__
    self.set_payload(_text, _charset)
  File "/usr/lib/python2.5/email/message.py", line 220, in set_payload
    self.set_charset(charset)
  File "/usr/lib/python2.5/email/message.py", line 262, in set_charset
    self._payload = charset.body_encode(self._payload)
  File "/usr/lib/python2.5/email/charset.py", line 386, in body_encode
    return email.quoprimime.body_encode(s)
  File "/usr/lib/python2.5/email/quoprimime.py", line 198, in encode
    body = fix_eols(body)
  File "/usr/lib/python2.5/email/utils.py", line 77, in fix_eols
    s = re.sub(r'(?<!\r)\n', CRLF, s)
  File "/usr/lib/python2.5/re.py", line 150, in sub
    return _compile(pattern, 0).sub(repl, string, count)
MemoryError

Ok. Setting a "low" ulimit for memory and vmemory, raise a MemoryError
on Linux too.

Chacking the same limits on FreeBSD, they are set to unlimited, so the
problem should not occour there.