Exim: defer 5XX errors

[klimenko_av]

By default Exim bounces when error series 5XX occurs. For instance:
530 5.7.1 Client was not authenticated
The question is: how to make exim defer such kind of errors

 

[nobaloney]

Bounces? Or refuses to accept? If you defer and then never can deliver what do want to do with the email?

Jeff

 

[klimenko_av]

it is necessary for us as outsources not to lose any emails if customer's MS Exchange Server is accidentally misconfigured. Our EXIM is relay (and spam filter) before customer's mail servers