The United States' relationship with Mexico fractured slightly after the initial National Security Agency spying reveal, so this latest one surely won't help. Turns out the NSA has full access to the President's email account. 

That pesky Edward Snowden released more documents to Der Spiegel showing hackers from the NSA's "Tailored Access Operations" department were able to infiltrate and "gain first-ever access to President Felipe Calderon's public email account," at some point during the 2010 summer. From there, NSA agents participating in the operation, internally dubbed "Flatliquid," were able to examine "diplomatic, economic and leadership communications which continue to provide insight into Mexico's political system and internal stability," according to Der Spiegel. The NSA called it a "lucrative source," of information. 

But another operation, "Whitetamale," carried out by the same division in 2009, helped U.S. agents craft how to maneuver with the Mexican counterparts. They gained access to high-ranking officials in Mexico's Public Security Secretariat, the division that leads investigations into the drug cartels, that helped U.S. officials craft how to maneuver and negotiate with their Mexican counterparts

This hacking operation allowed the NSA not only to obtain information on several drug cartels, but also to gain access to "diplomatic talking-points." In the space of a single year, according to the internal documents, this operation produced 260 classified reports that allowed US politicians to conduct successful talks on political issues and to plan international investments.

Knowing U.S. officials hacked the emails of high-ranking Mexican officials likely won't sit well with current Mexican President Enrique Pena Nieto. Previously, Snowden revealed the NSA was intercepting Nieto communications while he was on the campaign trail in 2012. The Mexican president's response was limited to asking President Obama to investigate any improper NSA spying. That was it. He didn't cancel any meetings or anything. Mexico's response to this scandal, so far, has been comparatively measured:

In response to an inquiry from SPIEGEL concerning the latest revelations, Mexico's Foreign Ministry replied with an email condemning any form of espionage on Mexican citizens, saying such surveillance violates international law. "That is all the government has to say on the matter," stated a spokesperson for Peña Nieto.

Whether or not the NSA can still access Nieto's email could change that.