How do I stop the iPhone from adding text attachments when I send pictures?
This is the fault of Microsoft Exchange and not specific to iOS.


  This happens because Microsoft Exchange Server is reformatting messages sent through it.
  
  The Exchange server insists that message text must always be first and attachments must always be last. As soon as the Exchange software sees one attachment in a message, it stops looking for text, and treats anything else in that message as an attachment. Any remaining text sections are converted into attachment sections, and given fake file names (like "ATT00001.htm").
  
  At this time, there is no way to make the Exchange server stop turning text sections into attachment sections. The only workaround is to include attachments at the end of a message, after text and after any signatures.


http://kb.mit.edu/confluence/pages/viewpage.action?pageId=4981187


  The body of a message is shown incorrectly as an attachment if you try to use an application in an Exchange Server environment to send a message that includes attachments





  Applies to Microsoft Exchange Server 2010 Enterprise, Microsoft Exchange Server 2010 Standard, Microsoft Exchange Server 2007 Enterprise Edition, Microsoft Exchange Server 2007 Standard Edition


http://support.microsoft.com/kb/969854