Hello @bsudabathula The Session token is valid only for 1 hour. If you will try to use that token then if will give your wrong ID/password error. You will have to work with adobe team to get a session token with no expiration time.
Note: Please replace server name as your instance URL
Once you will hit these URLs on the browser adobe will prompt to enter username password. Use MC credentials only shared by the support team.
2) Always use MC user credentials to generate session token and use the same in rtEvent WSDL's push event method
Your application server public IP from where you are calling Adobe Campaign Message Center API should be whitelisted. (Although this is not the reason for Invalid Login Password error). You will get 403 forbidden error and Response Null if IP not whitelisted.