error in all emails account :fail: no such address here

A lot of domains suddenly dont send/recieve emails , however the folder for every mail box pop still exist in /home/user/mail/domain.com/popuser

I also recognized that the file /home/user/etc/domain/shadow is not empty , and has all the accounts address.

this problem made all the clients not recieving emails , and the /var/log/exim_mainlog is full of messages with the meaning "no such user here" !!

NOTE : if we delete and recreate the same account it working .

we have found that the user is not listed in /etc/valiases/domain , if i add the user to this file all thing is back to working , any methode to fix /etc/valiases/ as we have almost 350 domain to do manually .