my admin has a very sensitive setup of Spamassassin which results in frequent false positives. Thus the subject is modified but worse the body is assembled of different attachments.
How can I despamassassin a modified message and turn it into the original message?
Besides adjusting your administrator with a clue-by-four, you can run it through spamassassin --remove-markup
However, this assumes the markup was made by spamassassin itself, not Amavis, MailScanner or one of several other tools that do their own markings and only use SA as a score generator.