我想解析包含IMAP响应的NSDATA，对于前
Date: Tue, 18 Sep 2012 02:50:54 +0000 (GMT)
From: xx@xx.com
To: yy@yy.com
Message-ID: 7034025
Content-Type: multipart/mixed;
boundary="----=_Part_16_9157073.1347936657899"
Message-Source: IMAP
------=_Part_16_9157073.1347936657899
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-ID: text.txt
Content-Location: text.txt
X-Section-ID: Text-Section
Test Message
------=_Part_16_9157073.1347936657899
Content-Type: image/jpeg
Content-Transfer-Encoding: binary
Content-ID: attachment_1
Content-Location: image_1347936646.jpg
X-Section-ID: Thumbnail-Section
ˇÿˇ‡ ...........
------=_Part_16_9157073.1347936657899--
由此我想要提取两个部分（文本和图像）。任何人都可以建议我使用Objective-c mime解析器。
注意：图像部分是二进制文件，不用base64编码。