So, if you could give details about your VO then probably members can help you better.
The latest (20th Aug) from London VO: Check saqisaqi's post: He received by Registered mail
Definitely not, certainly not for all visa offices.
Post-June-2010 at CHC London most applicants got their request by regular mail. We got ours by email - so if varies, I suspect just on the personal preference of the immigration officer reviewing the application.