Well, there was me, calmly dispensing advice on this thread in a 'been there done that' Yoda-ish way, and now my XH has done something that leaves even me flabbergasted 
Background: married since the year dot; he filed for divorce Easter 2011; divorce made absolute Jan 2012; finances finally sorted a year after that at FDR. XH now lives in a completely different part of the UK to DD (aged16) and me, with a woman who has a teenage son. The area XH lives in has very poor transport links by road and rail, so contact between him and DD has always been a bit of a logistical nightmare. He's also become increasingly involved with his new family and less willing to make the effort to see DD. Equally, she feels that her life & friends are here with me, so is reluctant to travel to see him. She backed out of a few things last year after tickets both for travel and events had been bought. I've felt for some time that I'm the only one out of the three of us who tries to maintain the relationship between them, as I truly want her to have a good relationship with her dad.
She's meant to be going skiing with her dad and his new family at half term, and she loves skiing. However, she hasn't seen him since September, and I don't think he skypes or emails her much. A few weeks ago DD said that she didn't want to go away with him, because whilst she likes skiing she didn't want to go with XH and his new family. I then quitely wrote to XH, telling him of DD's doubts, and urging him to contact her and say how much he was looking forward to seeing her, telling her about the resort etc, current snowfall, and generally bigging it up. No response, of course, as he is PA. (I don't email him because his emails were so abusive that I blocked his address.) I thought about things, and sent a second copy of the letter to his work address, just in case the first one had been purloined by his GF gone astray. The second letter has just been posted back to me by XH, unopened, and with no covering note.
There's nothing more I can do; this father-daughter relationship is dead in the water
. I tried so hard, but he's not interested, and that breaks my heart for DD. Obviously, I'm not going to let XH know how upset and angry I am (or indeed respond in any way) so I thought I'd just vent here. PA men; the gift that keeps on giving,