[exim] Aliased email returning as "Unroutable Address"

Over the weekend I had a mail server crash. Luckily I had a backup server ready.
Both servers were/are running Exim 4.34 and the configuration files were setup
the same way.

The problem I'm running into now is that local_delivery is working great but if
they have a mail alais setup in their domain's aliases file Exim is saying the
address is "Unroutable"

Here's the piece from my configuration file...

virtual_alias:
driver = redirect
allow_fail
allow_defer
domains = lsearch;/etc/exim/domains
data = ${lookup{$local_part}lsearch{/mail/${domain}/etc/aliases}}
user = exim
file_transport = address_file
pipe_transport = address_pipe
qualify_preserve_domain


I finally got everyone back online yesterday with their mail and at first the
aliasing was working fine. It was tested from the server and I was able to
send.

Now when I run a -bv command against an aliased account I get:

user@??? failed to verify:
Unrouteable address

Any help would be greatly appreciated. I have a live mail server that's
returning errors to valid email addresses and people are starting to get very
upset with me. I just can't see where the problem is, the setup is exactly the
same way and unfortunely the hard drive on the other server is completely
toasted so I can't double check the old configuration.

TIA