Question

Can putting a application form for a new job in with the business mail be considered an example of theft/ fraud at work?

Answer 1

ya it will consider

Answer 2

yes

This is unprofessional more than theft although technically if the business is paying for your private postage you are stealing from your employer. It would also look bad if the organisation to whom you had applied for the new job had noticed that your envelope had been paid for by your employer and they may question your honesty and integrity as a person.