CentOS 8.x postfix replace addresses on outgoing email

The below steps can be used to replace addresses (any address from, to, cc, etc.) on outgoing email. To replace addresses anywhere in email use:

Add below line in '/etc/postfix/main.cf'

smtp_generic_maps = hash:/etc/postfix/generic

Create the generic file '/etc/postfix/generic' with below content:
```
@localdomain.local	user@example.com
```

Create hash postmap of generic using:

cd /etc/postfix
chmod 600 sasl_passwd
postmap hash:/etc/postfix/sasl_passwd

Refer:

Anonymous