I would think they are allowed to keep them for as long as they wanted to. Whether they are required to keep them or, not is another issue, that I do not have the answer for.
Communication data, tax records, employment records, product records, transaction history
Hieroglyphics
It is required by the FASB and the government. It is your legal obligation.
Yes they do in order for the government to keep tax records and such
Very few people knew how to write in this time in history. No one knew how to read and it will be many centuries before the printing press is invented. So, writing didn't aid in expansion of trade. Trade was mainly the result of people connecting to others through war or need.
An employer is absolutely allowed to keep records on employees.
There are records retention laws and regulations in every state covering businesses and corporations. If the records actually were 'redundant" why would they keep more than one set anyway.
Encrypted email using a public/private key is very safe, providing that you keep your key secure. If it gets out, then your email is no longer secure. Medical records are covered under HIPPA, so you will need to check to see what methods they require to keep from violating the law.
Businesses typically keep their email lists and contacts confidential unless there is a motive for sharing the information. Sharing contacts can often mean revealing sales leads or business secrets.
It allowed the people to keep track of economic things and maintain records.
People and businesses use email filtering because there can be a lot of spam mail floating around. Filtering will keep you from receiving a lot of spam emails.
Yes you should keep some very good detailed records of all of your business operations. Go to the IRS gov web site at at top choose BUSINESSES You can click on the related links