Comment 154 for bug 357864

UX input: I definitely want this feature pref'ed off. This is very advanced stuff, and quite hazardous when used wrongly (users might not notice, or too late, that their important emails haven't been sent by server because they mis-tweaked their sender address). Just warning once imo is not enough.

I'm not happy with the warning text in comment 142.
E.g. the danger of failing to deliver is not even mentioned. Warning users against committing crimes is inappropriate for TB imo. It's probably not easy to get the warning right. The warning is less relevant when the feature is pref-ed off, so only people who really want this and know what they are doing will switch it on.

On the plus side, the gmail scenario is quite powerful, being able to create <email address hidden> on the fly might be useful. Otoh, I'm not sure how many usecases/scenarios there would be where I'd want to use such an email address only exactly once. For repetitive use (even 2 times), it's probably more useful to set up another identity on an existing account.