A typo frequently made by military officials has put millions of sensitive U.S. emails in the hands of an African country allied with Russia.

The U.S. military uses the email domain name ".MIL," which is sometimes misspelled as ".ML," the registered domain for the nation of Mali in West Africa. Emails intended to reach Pentagon officials, some containing diplomatic documents, tax returns, travel information, and other sensitive details, have mistakenly reached email accounts in Mali when the domain is misspelled, according to a report from the Financial Times.

A simple typo has caused millions of U.S. military emails containing extremely sensitive information to be misdirected to Mali—a close ally of Russia. The emails are being sent to Mali’s .ML domain thanks to people incorrectly typing the suffix of all American military email addresses, .MIL. Johannes Zuurbier, a Dutch internet entrepreneur contracted to manage Mali’s country domain, told the Financial Times he noticed the issue nearly a decade ago and has made repeated attempts to warn U.S. authorities about it.

(NewsNation) — A simple typo could have sent national security information as military emails were mistakenly sent to Mali, a Russian ally, and the problem has been going on for a decade.

Millions of emails were misdirected when people used the domain suffix .ml instead of .mil, which is used in all military email addresses. While the military has the .mil domain, .ml belongs to Mali, which has a Russian presence thanks to the mercenary Wagner Group, which has used the country to route supplies to Ukraine.