Enable a TLS with SMTP

backup ordinal config file: 
cp sendmail.mc sendmail.mc_orignal2019 


mkdir -p /etc/mail/certs 

cd /etc/mail/certs 
openssl req -new -x509 -keyout cakey.pem -out cacert.pem -days 365 
openssl req -nodes -new -x509 -keyout sendmail.pem -out sendmail.pem -days 365 

chmod 600 sendmail.pem 

We need to enable below list of parameters. 
vi /etc/mail/sendmail.mc 
define(`confAUTH_MECHANISMS', `LOGIN PLAIN DIGEST-MD5 CRAM-MD5')dnl 
TRUST_AUTH_MECH(`LOGIN PLAIN DIGEST-MD5 CRAM-MD5')dnl 

DAEMON_OPTIONS(`Port=smtp,Addr=10.70.9.12, Name=MTA')dnl 
dnl ### do STARTTLS 
define(`confCACERT_PATH', `/etc/mail/certs')dnl 
define(`confCACERT', `/etc/mail/certs/cacert.pem')dnl 
define(`confSERVER_CERT', `/etc/mail/certs/sendmail.pem')dnl 
define(`confSERVER_KEY', `/etc/mail/certs/sendmail.pem')dnl 
define(`confCLIENT_CERT', `/etc/mail/certs/sendmail.pem')dnl 
define(`confCLIENT_KEY', `/etc/mail/certs/sendmail.pem')dnl 

Compile the config file. 
m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf 

start saslauthd service 
service saslauthd start 

restart sendmail service 
service sendmail restart 

How to run SCP in background on Linux.

How to run SCP in background on Linux.

Source server: 192.168.1.1
Destination server: 192.168.1.10
File-size: 50GB
Filename: tech.dump


[root@sankar-paas ~]#nohup scp -r Tech.dump  techuser@192.168.1.10:/sankar-svn
nohup: appending output to `nohup.out'
skodipilla@192.168.1.10's password:     after password just press Ctrl+z

[1]+  Stopped                 nohup scp -r Tech.dump techuser@192.168.1.10:/sankar-svn

Then finally run below command.

[root@sankar-paas ~]# bg
[1]+ nohup scp -r Tech.dump techuser@192.168.1.10:/sankar-svn  &