Conditionalsecuritymultiparts, processsecuritymultiparts, retainsecuritymultiparts Channel Options

Processing within security multiparts
The,  , and   channel options control the handling of security multiparts, (that is, multipart/signed and multipart/encrypted parts), by the MTA&#x27;s message structure parsing code. They are particularly relevant for the conversion channel, as they control whether the conversion channel processes "inside" such multiparts. is the default: multipart/signed and multipart/encrypted are treated as monolithic and not "looked inside" by MIME message structure parsing. For instance, by default  the conversion channel won&#x27;t process any parts inside such parts. With, the conversion channel sees the parts inside the security multipart; note that enabling this breaks all signatures,   since the MTA redoes all the boundary markers during its MIME structure parsing. processes the multiparts similarly to, but retaining any "preamble" material inside the multipart.

See also:
 * Conversion channel
 * Attachments and MIME processing channel options
 * Channel options