[macspoofing]

>Is it allowed under GMail's TOS?

Do you even have to ask? The answer is a clear 'NO'. There is zero chance that Google will allow you to abuse their email service in this way.

I hope OPs personal account isn't in anyway related to this account because when 'guerillclick@gmail' is inevitably banned, his personal account may be collateral damage.

[eralpb]

you make a very good point, thanks for the warning.