The adhesion of the companies Google and Microsoft to the agreement "U.S.-E.U. Safe Harbor" presupposes, to date of today, that the particulars sent by the entity by virtue of the recruitment of the services Google Apps for Business or Microsoft Office 365 will be treated with determinate guarantees and conditions of security. Particularly, this treatment will stay in the case of the Microsoft company fully guaranteed, once the Resolution TI/00032/2014 of the Spanish Agency of Protection of Data has been attended to. However, it will be necessary to have present that the foreseen performances in the respective conditions of use of these services, especially of Google Apps for Business, they can exceed the main purpose for which the entity would entrust the treatment of the data. Likewise, in order to consider the safety measures suitable global implemented in these services, it will be necessary carry to term the foreseen auditing to the regulations of data protection. For what it makes, specifically, to the use of the service of electronic mail, this does not show additional risks for the security of the information whenever the recommendations made about this are adopted.