A new and improved method is provided for repairing or retrofitting cable management apparatus used in raised flooring systems constructed to deliver a source of building air, or HVAC, while managing cables passing through an access port constructed in the raised flooring structure without jeopardizing the underfloor plenum air delivery systems. More specifically the method of the present invention allows to improve the solvent stability of the polyimide membranes to solvents or solvent mixtures that would dissolve polyimide under the conditions applied during the filtration, such as dimethylforrnamide, N-methylpyrrolidinone, dimethylacetamide, tetrahydrofuran, y-butyrolacton, dimethylsulphoxide and chlorinated solvents. This and other information about the message is then sent by each member of an e-mail network to one or more central databases which stores the information and compiles statistics about e-mails sent by the sender to indicate the likelihood that the e-mail is unsolicited and determine the reputation of the sender.