Paul began this very personal letter with a customary salutation to set the tone for what followed. The salutation reveals that this was not just a personal letter, however, but it was also official. Paul wrote epistles to nine churches and to four individuals. Even though he addressed four of his letters to individuals, he undoubtedly intended that they too should be read to churches. [source][source][source]
"The opening and closing sections of the pastoral epistles vary considerably from the standard formulae. This suggests a calculated focus toward certain aspects of the author/reader relationship." [1][source]