Here is simple one liner for finding all mail aliases on Directadmin server that are forwarding to your email account – in this example your@email.com. All aliases are saved in files /etc/virtual/<domain_name>/aliases.
[root@directadmin ~]# grep -ri "your@email.com" /etc/virtual/*/aliases | awk -F '/|:' {'print $4 ": " $6 " ->" $7'} email.com: alias1 -> your@email.com somedomain.net: sales -> your@email.com,mail2@somedomain.net anotherdomain.com: chacha -> myaddress@anotherdomain.com,this@email.com,your@email.com . . .