when customer complain cannot able to email

 1. need to be root
 1. check /var/log/maillog
 1. ps aux | grep sendmail and ps aux | grep postfix
 1. if 3 shows nothing then need to start the mail service by
 1. service sendmail start or service sendmail postfix
 1. TJMNQ and TJMWA use postfix (non standard installation by tom mitch) , other server use sendmail
 1. run mailq to check outstanding email
 1. sendmail -q can force the sending of mail in the queue
 1. check to see why mail service stopped,  run  chkconfig to see if the mail service is on the list with runleverl 3 set to on if not that mean the service will not get start when restart computer run  chkconfig postfix/sendmail on  to make it auto start
 1. service sendmail restart , restart and see if it wrok.
 1. if not maybe something wrong with DNS , try ping one of the address in the mail queue.
 1. if it was not pingable then try to ues a different DNS in the resolve.conf. 8.8.8.8 is the google one
 1. after changing dns best to restart the sendmail. before running the sendmail -q
 1. if savemail complain cannot save rejected mail anywhere , then it maybe have to do with the permission in /vr/spool/mail directory.