The authentic Pauline corpus
My own relatively uninformed view on the undisputed/disputed status of the canonical Pauline corpus runs as follows:
Genuine Pauline authorship
Romans, 1 and 2 Corinthians, Galatians, Philippians, 1 Thessalonians, Philemon and ... Colossians and 2 Thessalonians
Likely Pauline authorship
1 Timothy, Titus
What thinketh thee? I am very open minded and flexible on these matters, and I am yet to get into E. Randolph Richards’s, Paul and First-Century Letter Writing, which may change my mind on a fair bit. I think it may as my notion of 'authorship' probably needs more work.
Peter Stuhlmacher writes about "Paul's" authoriship of the disputed letters (note the ""). That seems a bit clumsy to me, but it is perhaps one way to negotiate the matter.
For me, despite some earlier canon-choosing criteria, the text doesn’t need to be written by Paul for it to be inspired, to be useful for the church. Truth is a multifaceted creature, difficult to pin down in only one or two directions; and neither will inspiration be confined to a test-tube. So the truth of Titus, for example, is not to be located in that the historical Paul did or did not write it; it remains as much scripture for the church as 1 Thessalonians, as much a part of the NT canon as any other text which God has led the church to recognise.