diff --git a/Lib/imaplib.py b/Lib/imaplib.py

index 4586fb3..d8243e5 100644

--- a/Lib/imaplib.py

+++ b/Lib/imaplib.py

@@ -37,11 +37,12 @@ AllowedVersions = ('IMAP4REV1', 'IMAP4')        # Most recent first

 # Maximal line length when calling readline(). This is to prevent

 # reading arbitrary length lines. RFC 3501 and 2060 (IMAP 4rev1)

-# don't specify a line length. RFC 2683 however suggests limiting client

-# command lines to 1000 octets and server command lines to 8000 octets.

-# We have selected 10000 for some extra margin and since that is supposedly

-# also what UW and Panda IMAP does.

-_MAXLINE = 10000

+# don't specify a line length. RFC 2683 suggests limiting client

+# command lines to 1000 octets and that servers should be prepared

+# to accept command lines up to 8000 octets, so we used to use 10K here.

+# In the modern world (eg: gmail) the response to, for example, a

+# search command can be quite large, so we now use 1M.

+_MAXLINE = 1000000

 #       Commands