如果将cover letter作为email的形势发过去，应该是写在email里，resume 放attachment 里。
这样的话，cover letter中需要写自己和employer的地址么？看了些sample 需要些，但觉得作为email的话是不是有点罗嗦了？

Either way is fine.  I never included my/employer's addresses though in the emails.

Keep the cover letter simple, state what position you are looking for. When i hire people, i barely read the cover letter, pretty much go straight to the resume and spend one minute scanning before making a decision.