Thanks for all the replies! I've been a bit too busy lately! Anyway, in reply to HT:

Why would you want to know when they come online?

Sorry, that's not what I meant...what I was trying to say was that I was trying to find a program which would constantly ping the IP until it was found to be active (but if it has a decent firewall it will just drop the ICMP packets) - yet, this is pointless, because I don't even know their IP! :P slinky2004: 83.201.1.85 is another Wanadoo IP - one of their servers, if I'm not mistaken...

As for the sender having a dynamic IP address - I bow down to you, almighty HT! Maybe it's because of the fact that so few people here use DSL that we use PPPoA (with static IPs), that's why I incorrectly assumed that most DSL users had static IPs. Hehe! Well, thank you for correcting me, and I guess I've learned something!

I don't think my ISP would view a series of pings as an attempt at Ping Flooding or DoS, because of the fact that they're so rubbish! I literally lose my internet connection approximately once every day, and the technicians there are pathetic (whenever I call them up asking them what's wrong, they tell me that there's something wrong with their servers - and they've caught more than one virus and trojan in the past!). Theirs could though, as you said.

Hit that junk mail button and continue on with your day..

You're right! Plus (I know this is a number one rule of what NOT to do) I already replied to them, because it wasn't really a spam email - it was a "Hi, how are you? How's everything over there?" one, and the person was called the same name as one who I recently gave my email address to (I'm not actually sure if I did or not). Although, it could just be spammers trying to check if my address was active, but I doubt it. The email was just too personal...

Thanks everyone for all your help! I've really learnt a lot from this thread, so thank you!