How to check mail logs :

How to check mail logs :
1] tail -f /var/log/exim_mainlog
2] grep few domains which are present in mail logs to check whether domain is on our server. and if domains are not present on our server then check with the mail IDs e.g. mail ID is => 1J9ZRu-0003Zx-Kf-H
3] cd /var/spool/exim/input/u       //there are 0 to z directories  but i choose “/u” bcoz mail ID contain u before “-”   e.g. 1J9ZWu-0006Xh-AN //
4] cat 1J9ZWu-0006Xh-AN            // cat those mail IDs untill you get the script , if mail is  delivered then after this cat cmd you will get message no such file here if that mail is not delivered then u will  get script in which domain is present which is available on our server suspend it if  increases server load again and again. and send those logs to all
5] cat n1J9ZFu-00060H-UM-H
6] cat 1J9ZKu-0000lK-Ch-D   ……………