Once the letter became Biblical Canon, it's pretty much an open letter to all.<quoted text>philippians 1:1 paul and timotheus the servants of jesus christ, to all the saints in christ jesus which are at philippi with the bishops and deacons... you reading some one elses mail? shame on you yes?
Sounds like you've begun reading it too, yes?
In Paul's letters the greeting or praescriptio follows a standard form, though with variations. It is based upon the common Greco-Roman epistolary practice, but with the addition of Semitic and specifically Christian elements. The three basic components are: name of sender; name of addressee; greeting. In identifying himself, Paul often adds phrases to describe his apostolic mission; this element is more developed in Romans than in any other letter. Elsewhere he associates co-workers with himself in the greeting: Sosthenes (1 Cor), Timothy (2 Cor; Phil; Phl) Silvanus (1 Thes-2 Thes). The standard secular greeting was the infinitive chairein, "greetings." Paul uses instead the similar-sounding charis, "grace," together with the Semitic greeting salom (Greek eirene), "peace." These gifts, foreshadowed in God's dealings with Israel (see Numbers 6:24-26), have been poured out abundantly in Christ, and Paul wishes them to his readers. In Romans the Pauline praescriptio is expanded and expressed in a formal tone; it emphasizes Paul's office as apostle to the Gentiles. Romans 1:3-4 stress the gospel or kerygma, Romans 1:2 the fulfillment of God's promise, and Romans 1:1, 5 Paul's office.