Many thanks George !

In fact, my question was erronous. It sould be "what should be the
string which I have to return when leaving my own ruleset 98, in order
to say: send to the user ..... via the host .... using the mailer
......" . In fact this information is exactly the special triple to
which one the ruleset 0 have to resolve to, but when leaving my own
ruleset 98, I do not have to resolve to this triple because the
processing will continue especially with the Parse1 ruleset.