You could try the sanitizer that remove attachment's from mails ( anomy-sanitizer it's the full name i guess ) I have this in a text file , maybe could help you

1) ripMIME (http://pldaniels.org/ripmime/): "extract the attached files out of a MIME package (as say produced by programs such as AMaViS, Inflex and cInflex)." Does this mean that it ripMIME will only work if an antivirus software first manipulates the message? or will it work if say postfix passes the message to procmail which then passes it to ripMIME? Doesn't mention if a message gets added to the email notifying the recipient that an attachment was removed.

2) aradis (http://robur.slu.se/jensl/aradis/): "The removed attachment is sent to a specfied resource for storage. The attachemnt is replaced with a notice of where the removed attachment may be found. " I like the feature of informing the recipient that an attachment was removed.

3) batemail (http://batemail.sourceforge.net/): "it takes input on STDIN, searches for (and possibly removes) MIME attachments with a given filename extension, and pipes the output to the local mailer." specifically mentions procmail (which i use) and i assume it will work with any MTA because it simply accepts the output from procmail and returns it back to procmail. Option to place a notice that attachment was removed? theoretically it sounds possible since the output goes back to procmail... maybe have a rule in procmail to add a line to the body of the message using formail?

4) protector (http://www.lowth.com/protector/): "replaces the offending attachments with standard warning messages (or modifies them to remove the dangerous parts)" ..."blocking ALL BUT a listed set of types". This means that i have to think of a list of innocent/harmless file types... this seems harder (because i could forget a file type that i don't personally use but other do) than just excluding known bad/potentially harmfull filetypes.

5) MIMEDefang (http://www.roaringpenguin.com/mimedefang/): "Delete or alter attachments based on file name, contents, results of a virus scan, attachment size, etc."... "Customize filter rules based on domain, user-name, relay machine, etc."... "Add boilerplate text to e-mail messages"... "Add or delete recipients for a message." Seems like the one with the most options... or is it just the one with the most useful/complete explanation on the website?