most high stakes governments monitor their web pages religiously (think covert op hackers), and its monitored 24/7 by staff, intelligence, sometimes horses in the field, but if you want to share nice words with the president (bad words mean you get interrogated so severely they break your teeth =/ ) the link is
https://www.whitehouse.gov/contact (click here)
fill out the form to your best of knowledge (think tax forms) and put in your sincere thoughts, threats, violence, illegal acts will get you interrogated severely and placed in protective custody until the powers wherein decide, but constructive thoughts may result in an actual email you can print out and read, from people who interact with The President, on The Presidents behalf! I’ve received two emails from the White House through this contact form, out of thousands of suggestions.. Let’s just say theres no turning back after the parties =/ (basically theres no cure for hangovers just yet, right tv?)
Here’s a song to get you started, try to contribute as much as you can to your country, you never know when they’ll repay you