Fax machines. Phone lines are pretty private, and sending a fax is usually more secure than emailing something, especially if someone else manages your email.

If someone is 1900 miles west of you, they will be in (almost) your exact same physical location after a short time (about two hours). If someone is 1900 miles south of you, they won’t. So it depends on the cardinal directionality.

That being said, 1900 miles isn’t that far relative to the circumference of the earth (~25,000 miles), so someone 1900 miles south of you would see mostly the same sky. You’d each see some stars the other couldn’t see, but only near the horizon. About 85% of the sky would be the same (if you could see perfectly to every part of the horizon).