2. The Subscript of the Epistle is suspect. It was written at Ephesus, not Philippi.
In the Greek Codices, the subscript thus reads: πρὸς Κορινθίους πρώτη ἐγράφη ἀπὸ Φιλίππων διὰ Στεφανᾶ, καὶ Φουρτουνάτου, καὶ Ἀχαικοῦ, καὶ Τιμοθέου, The first epistle to the Corinthians was written from Philippi by Stephanas and Fortunatus and Achaicus and Timotheus. The Syriac and the Arabic have the same. But this subscript is suspect, because the Apostle himself in 1 Corinthians 16:8 appears to indicate that it was written, not at Philippi, but at Ephesus. Which Athanasius, Chrysostom, and other ancients also thought. And neither do the words in 1 Corinthians 16:5, Μακεδονίαν διέρχομαι, I pass through Macedonia. For, while writing this, he did not pass through Macedonia, but indicates that he was soon going to pass through, so that διέρχομαι, I pass through, is put in the place of διελεύσομαι, I will pass through.