It is interesting that Chapa (see previous post) supports Stirewalt's view, that Paul's letters were 'official letters in a loose sense' (pp. 651-2). He makes a number of points on this:
- although occasional, Paul's letters are not private, but are rather public: 'a kind of public document'
- Paul has an 'authoritative position in relation to the recipients'
- The mention of co-authors and so-senders bestows an official character.
- The letters would probably have been received as official letters.