In many states sending spam is illegal. thus, the spammers have techniques to try and ensure that no one knows they sent the spam out to thousands of users at a time. which of the following best describes what spammers use to hide the origin of these types of e-mails? a. a blacklist of companies that have their mail server relays configured to allow traffic only to their specific domain name. b. mail relaying, which is a technique of bouncing e-mail from internal to external mails servers continuously. c. a blacklist of companies that have their mail server relays configured to be wide open. d. tools that will reconfigure a mail servers relay component to send the e-mail back to the spammers occasionally.

B. Mail relaying, which is a technique of bouncing e-mail from internal to external mails servers continuously.

Explanation:

In the field of computing, spam refers to unsolicited, repeated e-mails which are sent by malicious users, known as spammers, with the intention of distributing advertisement, propaganda, scams, or luring unsuspected users to malicious websites. Spam is illegal in many states, and spammers can be subject to fines or even prison. Thus, spammers rely on techniques to hide the origin of their spam in order to avoid liability. The most common way to do this is by sending spam through what is known as mail relayers, that is, e-mail servers which are tasked with relaying the e-mail sent to them to other external mail servers. This is done in a very simple way: spammers send an e-mail to the mail relaying service, including a list of e-mail addresses to which said spam mail must be relayed to. The server then relays the e-mail, inadvertenly spamming the mentioned e-mail addresses. In order to avoid this, most mail relayers have tried to implement safeguards, such as requiring users to authenticate themselves before resending any e-mail, and automated systems such as algorithms that learn how to detect spam and block it automatically.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.

marginal cost is a microeconomic measure that us to evaluate the extent to which the level of production of a good is sustainable in accounting, that is, to how many quantities the company plans to profit from the production of the good.

the concept of marginal cost is simple, it means the cost of producing one more item. for example, in the case of pies, the marginal cost is the cost of producing one more pie than those that have already been produced.

it is important to understand that productive activity influences marginal cost. the marginal cost of some goods can be very high, while others may be insignificant. for example, the marginal cost of producing an extra plane is very high. already the marginal cost of a water company to provide 1l more water is derisory.

in the case of pies, the cost involves the inputs, the labor and the fixed cost, which involves the fixed space of the bakery. the level of production initially has the marginal cost decreasing because there is space and manpower available. however, to produce more you have to hire more workers and buy more inputs. if physical space is limited, workers will conflict with places, inputs and their productivity will decrease, meaning there is an optimum point of production for each level of space and manpower. from this point on, the productivity of the workers will be getting smaller because of lack of space, so that the marginal cost of producing one more pie will be increasing. so, although you have not posted the chart, but if you have the answer, you can see that my explanation goes according to the marginal cost curve that will increase from the 4th pie, answer (c).