[exim] Callout=reject

Hi

Is there a possibility to change the behaviour when a mailserver rejects
empty "mail from"

I know that according the RFC's people should accepts an empty return
path, but a lot of servers reject
Mail from:<>

As a result the callout fails ... but I want to know if this is tunable

E.g. consider the rejection below as a defer

Mail from:<>
501 Syntax error in address

E.g.
Mail from:<>
250 OK
Rcpt to:<test@???>
550 5.1.1 <test@???> is not a valid mailbox


Is there a possibility to differ between those 2

Thanks

Ronny




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