[tor-talk] SMTP & POP3 Email over Tor.. Anonymity breaking?

[Anon Mus]

Hi,

Is it true that email SMTP & POP3 hosts (e.g. gmail's servers) can 
obtain from SMTP & POP3 clients (e.g. Thunderbird) data such as,

1. client time zone
2. client machine clock time
3. client machine time since last boot

even though its over Tor?

If so, can't these be used to trace a client machine which might also be 
accessing other, say gmail, accounts via the open internet (not via Tor) 
? (I know it sounds paranoid, but surely it is theoretically possible)

And ... is there ANY software/email clients out there that can 
counteract/obfuscate this kind of tracing, say by changing the 
parameters returned? (Preferably Windows OS but others will do if available)


Thanks,

Jo