I'm using SpamAssassin to tag spam and prefix the spam score to the subject line. To make the scores sort properly in the client's message list, I pad the score with spaces to right-align it.

It looks like dovecot-0.99.10.9-1.FC3.2 is frustrating this by stripping the excess spaces from the subject before reporting it in FETCH responses. Here's an actual subject line:

Subject: (SPAM? 6.9) Urgent Response !!

Note the multiple spaces before the "6.9". Here's the matching FETCH command and reply, as reported in Mulberry's IMAP.log (just the relevant message is shown here):

A00035 FETCH 1507:1524 (FLAGS RFC822.SIZE UID INTERNALDATE ENVELOPE BODYSTRUCTURE)

• 1517 FETCH (UID 1557 FLAGS (\Seen) INTERNALDATE "02-Oct-2004 12:24:40 -0700" RFC822.SIZE 6263 BODYSTRUCTURE (("text" "plain" ("charset" "us-ascii") NIL NIL "8bit" 1168 24 NIL ("inline" NIL) NIL)("message" "rfc822" ("x-spam-type" "original") NIL "original message before SpamAssassin" "8bit" 3855 ("Sat, 02 Oct 2004 13:52:28 -0400" "Urgent Response !!" (("Dr. Price" NIL "pkprice2i" "netscape.net")) (("Dr. Price" NIL "pkprice2i" "netscape.net")) (("Dr. Price" NIL "pkprice2i" "netscape.net")) NIL NIL NIL NIL "E1CDo3Y-0002FZ-9f@host.cell04.com") ("text" "plain" ("charset" "us-ascii") NIL NIL "7bit" 2731 35 NIL NIL NIL) 63 NIL ("inline" NIL) NIL) "mixed" ("boundary" "----------=_415F007A.0DECCC93") NIL NIL) ENVELOPE ("Sat, 02 Oct 2004 13:52:28 -0400" "(SPAM? 6.9) Urgent Response !!" (("Dr. Price" NIL "pkprice2i" "netscape.net")) (("Dr. Price" NIL "pkprice2i" "netscape.net")) (("Dr. Price" NIL "pkprice2i" "netscape.net")) NIL NIL NIL NIL "E1CDo3Y-0002FZ-9f@host.cell04.com"))