--- trunk/Lib/imaplib.py	2010-04-03 14:57:03.000000000 +0200
+++ trunk-new/Lib/imaplib.py	2010-04-03 15:23:24.000000000 +0200
@@ -34,6 +34,7 @@
 IMAP4_PORT = 143
 IMAP4_SSL_PORT = 993
 AllowedVersions = ('IMAP4REV1', 'IMAP4')        # Most recent first
+MAX_CHUNK = 64000
 
 #       Commands
 
@@ -232,7 +233,19 @@
 
     def read(self, size):
         """Read 'size' bytes from remote."""
-        return self.file.read(size)
+        # don't read too much data at once
+        if size <= MAX_CHUNK:
+            data = self.file.read(size)
+        else:
+            chunks = []
+            read = 0
+            while read < size:
+                length = min(size - read, MAX_CHUNK)
+                datum = self.file.read(length)
+                read += length
+                chunks.append(datum)
+            data = ''.join(chunks)
+        return data
 
 
     def readline(self):