skripta:

#!/bin/bash
for (( i = 5; i >=0; i-- )) ; do
     grep $(date +%T -d "-$i  min") /var/log/exim4/mainlog  >> /home/drot/5min.log | cat /home/drot/5min.log | awk '/=>|<=/{print $2 " " $4 " " $5}'
done

output:

17:23:02 <= root@eu-softing.com
17:23:02 => davor.rotim@eu-softing.com
17:23:02 <= root@eu-softing.com
17:23:02 => davor.rotim@eu-softing.com
17:23:02 <= root@eu-softing.com
17:23:02 => davor.rotim@eu-softing.com
17:23:02 <= root@eu-softing.com
17:23:02 => davor.rotim@eu-softing.com
17:23:02 <= root@eu-softing.com
17:23:02 => davor.rotim@eu-softing.com
17:23:02 <= root@eu-softing.com
17:23:02 => davor.rotim@eu-softing.com