If he's never done this when postie comes before, something has happened - either he is unwell 0r else postie has annoyed him by shouting, or accidentally banging him on the head with a heavy letter! I'd heard postmen in the past swearing at dogs who are just barking - OTOH we have a fab postie who our dog really likes

Yes - keep him under control and give him extra special tasty food titbits when postie comes - keep him as far away as you can to start with as he reallyneeds to be in his comfort zone where he doesn't react, then gradually get him closer over a period of time :)
Lindsay
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