[Exim] Checking Quotas at SMTP time

Hi!

I'm trying to enable checking quotas when doing the verification for the
SMTP RCPT command. I found the FAQ entry and acted according to it, but:

It does work, either with ACLs with 'condition = ${run {...' or
with a queryprogram-Router set to 'verify_rcpt=true', but I am only able
to fail the message completely, not just temporarily reject it with a
useful message. 'Temporary local problem' seems a bit misleading here.

Is there any possibility to return a temporary error with a custom error
message?

Thanks in advance,
Heinz Ekker