JAMES-3574 LMTP MailetContainerHandler should return one response per RCPT

This hook was not spec compliant...

https://datatracker.ietf.org/doc/html/rfc2033#section-4.2

```
   [...] the server returns one reply
   for each previously successful RCPT command in the mail transaction,
   in the order that the RCPT commands were issued.  Even if there were
   multiple successful RCPT commands giving the same forward-path, there
   must be one reply for each successful RCPT command.

```
3 files changed