How to configure osgi config xml under config folder programatically?

I tried with as MessageGatewayService well, it is taking from address from osgi config but Name is working.

e.g.

email.setFrom("abcd.efg@gmail.com", "Arun Patidar");

aem63app-repo/HTMLEmailServlet.java at master · arunpatidar02/aem63app-repo · GitHub

I am not sure, if there is any other configuration to work above but if you really want to go with config update then you can use below  code :

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Configuration configuration = configAdmin.getConfiguration("com.day.cq.mailer.DefaultMailService");

if (configuration != null) {

// get properties

Dictionary<String, Object> properties = configuration.getProperties();

Dictionary<String, Object> newProperties = properties;

// update properties

        if (properties == null) {

        newProperties = new Hashtable<String, Object>();

        }

        newProperties.put("smtp.user", "new user");

        newProperties.put("smtp.password","new pass");

        newProperties.put("from.address", "new from");

configuration.update(newProperties);

// send mail

// revert to old property

configuration.update(properties);

}