Fw from manual Errata:

------ mamurillo@rslcom.es --------
Investigating and fighting with imap functions I think I've discovered that counting parts for imap_fetchbody function fails with forwarded messages. 
When I count parts (1, 2, 2.1 etc..) it seems that for a forwarded message insert one part more. For example the part counted as 2.1.2 is the part 2.2 for the imap function. With normal multipart messages do it well, but forwarded messages.Could anyone confirm that I think I dicovered? 
If is true take care about this class of message.
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------ owain@vaughan.com ------------
mamurillo@rslcom.es is right. With forward messages that have a text/plain (2.1.1) and text/html (2.1.2) subparts of a multipart/alternative part (2.1) the imap_fetchbody function returns nothing for parts 2.1.1 and 2,1,2, but returns the parts when a request is made for 2.1 and 2.2. Is this a bug?
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I am not familiar with IMAP and could not verify this but it seems bugish to me.

James