The current connection is being closed.
||xxfi_close is always called once at the end of each
||Do nothing; return SMFIS_CONTINUE.
||Opaque context structure.
- xxfi_close may be called "out-of-order", i.e. before even the
xxfi_connect is called. After a connection is established by the
MTA to the filter, if the MTA decides this connection's traffic
will be discarded (e.g. via an access_db result), no data will be
passed to the filter from the MTA until the client closes down. At
that time, xxfi_close is called. It can therefore be the only
callback ever used for a given connection, and developers should
anticipate this possibility when crafting their xxfi_close code. In
particular, it is incorrect to assume the private context pointer
will be something other than NULL in this callback.
- xxfi_close is called on close even if the previous mail
transaction was aborted.
- xxfi_close is responsible for freeing any resources allocated
on a per-connection basis.
- Since the connection is already closing, the return value is