Once again, Henrik is the man: http://www.nabble.com/CONNECT-errors-with-2.7.STABLE2-2-td18261153.html What I'm looking for is a brief, technical explanation of why this setting defaults to off rather than on. I didn't really get from that thread why the defaults were the way they were, especially as the behaviour described with the Expect 100 wasn't in violation of spec, just unusual. We had a problem which was solved by this setting, and I want to be in a position to explain why things were setup in a way which caused this issues to occur. Thanks, Paul Cocker TNT Post is the trading name for TNT Post UK Ltd (company number: 04417047), TNT Post (Doordrop Media) Ltd (00613278), TNT Post Scotland Ltd (05695897), TNT Post North Ltd (05701709), TNT Post South West Ltd (05983401), TNT Post Midlands Limited (6458167)and TNT Post London Limited (6493826). Emma's Diary and Lifecycle are trading names for Lifecycle Marketing (Mother and Baby) Ltd (02556692). All companies are registered in England and Wales; registered address: 1 Globeside Business Park, Fieldhouse Lane, Marlow, Buckinghamshire, SL7 1HY.