Hello billygoatkaraoke,Glad to see you )
Hijacked is it means hacked ? or?
Well if your password stealed for that email possible reasons:
1) Do not use same passwords everyvere(This is possible from database which you are signuped yet with that password dump your password(hash) then submit to online md5 crack sites + if you are using weekness passwords this is possible)
So,do not use same password everyvere and use instead different passwords for different services.
2) This is also possible to gain password through Phishing attack.
3) This is also possible to hack your website or hosting company then get that your password
4) This is possible bruteforce against your account(facebook,msn,etc etc) and gain your password.
5) This is possible too infect your computer with some troyan dropper then drop keylogger+steal your passwords+then self destroy that keylogger on your computer without traces!(Antivirusses s*cks)
6)Use legal and only from oficial softwares(Do not use warez etc etc) this is possible to steal your passwords with backdoors(which is included 80% of warez)
7)Use Firewall to secure your network(because this is possible locally(frm local network) sniff your traffic(ARP spoof) then get your password while it transmits over network)

Do not use public aka 'FULLY ANON ELITE proxies' in fact such services is sniffer!
9) Do not sit on public computers(Inet Cafe,Free Wifi) (Again Sniffing or DNS Spoofing and your passwords can be stealed!)
10) Possible but is not common: May be your ISP was compromised and backdoored(Possible to sniff passwords or again DNS spoof)
Use VPN or at least Surf Over SSH(BTW,Protects from SSL Beast)
Etc etc...
+
mail($emailTo, 'blah blah', $body, 'From: $myEmail');
Using such services spammers+'scriptkiddiez' can do more bad things! In ex: Mail to someone with bad things etc etc nasty.
I think it is abused and thats why your account Suspended from your hosting.
day long without having to know the 'From' address password.
Sure!
Use that code only for your personal works and do not public it otherwise it will be abused.
I would recommend to you 1'st ckeck for spyware+rootkit(Use Unhackme<=What a Great programm!!!)
Then secure your machine use Firewall (In ex: Comodo ISS which is free for peronal use)
Then change all your passwords +secret question+secret answers to all your mails,accounts,etc.
And Be Paranoia like me xD))
Cheers.