wtf?

i really don't get this. my ex got in touch last week, with a question that was apparently important to him. which led to several emails back and forth, the last one seemingly saying 'goodbye'. like that was it, we'd never talk again. by the time i replied, wondering if i'd missed something, he'd already closed his email account. what the hell? he got in touch with me 7 years ago, out of the blue, with a one-liner. on/off sporadic emailing followed on through the years. he even called me once, all the way from Australia. and now suddenly, while we were having a nice exchange (he sent me 4 emails in 5 days), it all just ended. and i'm just wondering, what the hell happened? what was that all about? why answer my emails and make me think about our relationship with all his questions, if all he wanted to do was close his email account? if he'd just closed it, i wouldn't have thought about it. part of life kind of thing. but now i actually feel like shit. like he's made me miss him and it's like we've broken up all over again, except i have no idea why.