Ok, many thanks to Andrey Melnikov that, offlist, helped me. Finally i've solved my issue with SRS. Because could be useful to others, i post my findings here.
1) the ''bounce'' router HAVE TO EXIST and HAVE NOT the 'no_verify' option set; Doing the rewrite, exim verify that the SRS-generated local address exist, and refise to redirect to non-working addresses. My bounce router currently is: .ifdef SRS_SECRETFILE srs_bounce: debug_print = "R: srs_bounce for $local_part@$domain" driver = redirect domains = +local_domains allow_fail allow_defer local_part_prefix = srs0+ : srs0- : srs0= : srs1+ : srs1- : srs1= caseful_local_part address_data = ${run{/bin/sh -c "/usr/bin/srs --reverse --secretfile=SRS_SECRETFILE --hashlength=SRS_HASHLENGTH ${local_part_prefix}${local_part}@${domain} 2> /dev/null data = ${quote_local_part:${local_part:$address_data}}@${domain:$address_data} .endif Because the hash may contain the '/' character, the local part character restriction have to be relaxed: CHECK_RCPT_LOCAL_LOCALPARTS = ^[.] : ^.*[@%!|`#&?] Then, the router that do the SRS rewriting set the errors_to: .ifdef SRS_SECRETFILE address_data = ${run{/bin/sh -c "/usr/bin/srs --secretfile=SRS_SECRETFILE --hashlength=SRS_HASHLENGTH --alias=SRS_DOMAIN $sender_address 2>/dev/null"}{$value}{:fail: SRS failure}} errors_to = ${quote_local_part:${local_part:$address_data}}@${domain:$address_data} headers_add = "X-SRS: Sender address rewritten from <$sender_address> to <${quote_local_part:${local_part:$address_data}}@${domain:$address_data}> by $primary_hostname." headers_remove = SRS_HEADERS_REMOVE .endif This not suffices. A rewriter have to be addedd. In debian, the easest way is to define: REMOTE_SMTP_HEADERS_REWRITE = *@* "${if !eq{$h_errors_to::}{}{$h_errors_to::}{$sender_address}}" s Also, if you want some logging, you can set: MAIN_LOG_SELECTOR == MAIN_LOG_SELECTOR +address_rewrite +return_path_on_delivery +sender_on_delivery A little note. If i set REMOTE_SMTP_RETURN_PATH, that seemed to me the right option, not only does nothing, but also the rewrite stop working. Boh. If someone can explain me... Thanks. -- STOP. I wanna go home take off this uniform and leave the show (Pink Floyd) -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/