If we enable OpenPGP processing, like in `config.ini`:

```
[pgp]
enable = yes
roles =
homedir =
encrypt = yes
require_incoming = encrypted
```

we lose email under some conditions:
In the case some user sends in a report and the bounce email
address cannot be encrypted to.

This can be seen in the code of mailer.bounce_message()
If the first `if crypto_to` does not find pubkeys then no
attempt of sending is made. Same with the next `if crypto_to`.


changeset:   5241:092c4522b3bf
adds some debugging diagnostics so the problem can be observed.

A better solution would be to send and unencrypted message without body
and the long one to the admin or dispatcher so that they notice the
problem of missing keys and can resolve it. Otherwise if anlegitimate
user sends an email with infos making an mistake, those infos are lost
without notice to anyone.

hg5241:092c4522b3bf

One condition to lose emails is that config.ini additionally has
```
[main]
error_messages_to = user
```

If this is set to "both" or "dispatcher" the bounce will go to the
dispatcher unencrypted.