Русско-англо-русский юридический словарь

A written contract as the name suggests, is a contract whose terms have been reduced to writing. Written contracts are also commonly signed. However, a written contract may consist of an exchange of correspondence, a letter written by the promisee and assented to by the promisor without signature, or even a memorandum or printed document not signed by either party. (definitions.uslegal.com)

Having lost the case in Romania he took it to the Human Rights Court in 2008, arguing that his employer’s decision to end his contract was based on a violation of his rights to private correspondence. (Telegraph)

The secrecy of correspondence (German: Briefgeheimnis, French: secret de la correspondance) or literally translated as secrecy of letters, is a fundamental legal principle enshrined in the constitutions of several European countries. It guarantees that the content of sealed letters is never revealed and letters in transit are not opened by government officials or any other third party. (Wikipedia)

The President, at his own discretion, may, or upon the written request of five (5) members, shall, call a meeting by correspondence and the President shall fix the date thereof. A notice of the call of any meeting by correspondence shall be given by the Executive Secretary in writing by mail to each member and shall be postmarked not less than ten (10) days prior to the date fixed for any such meeting by correspondence, which notice shall state the manner of call of said meeting by correspondence, state the date fixed for said meeting by correspondence, contain the subject or subjects to be voted upon at such meeting together with the text of any resolutions or any other actions proposed for vote and contain a ballot form of subjects corresponding to the agenda by which the members may register their votes upon any or all of subjects set forth in the agenda for such meeting by correspondence. (United States Seaports: Alaska, Pacific Coast, and Hawaii)