actually, multiple mailings of resumes are considered poor form. at least at my company and any one i've ever been at in the 10 years since college. exception: if you fax it and note at the top that it will also follow via u.s. mail.
most companies, do prefer email though--look at earthlink's open positions list--they state a preference for email, as most tech companies do.
anyway, just trying to help as someone who's been out in the world and in h.r. and related fields for awhile.
size of envelope will not matter.
|