、。
This letter contains sensitive information and may cause offense.
Literal
This-letter [location-には] delicate information [subject-が] is-contained-[formal-conjunctive-ており], feelings [object-を] harming-occurrence [subject-が] exists-[might-かもしれない].
A formal written warning, typical of legal or business correspondence. 含まれており is the formal/written equivalent of 含まれていて — the ~ており form is the formal continuative of ~ている, linking clauses without dropping register. 気分を害する ('to offend, hurt someone's feelings') is a set phrase. ~ことがある ('there are occasions when... / may sometimes') combined with かもしれない ('might') creates a cautious, covering-all-bases warning. The overall register is stiffly formal.