Н. В. Моина ю. Б. Генина т. В. Шульженко чтение английской научнотехнической литературы
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IMAP Problems and AttachmentsYour e-mail client connects to the IMAP server using port 143. The e-mail client then issues a set of text commands that allow it to do things like list all the folders on the server, list all the message headers in a folder, get a specific e-mail message from the server, delete messages on the server or search through all of the e-mails on the server. One problem that can arise with IMAP involves this simple question: "If all of my e-mail is stored on the server, then how can I read my mail if I'm not connected to the Internet?" To solve this problem, most e-mail clients have some way to cache e-mail on their local machine. For example, the client will download all the messages and store their complete contents on the local machine (just like it would if it were talking to a POP3 server). The messages still exist on the IMAP server, but you now have copies on your machine. This allows you to read and reply to e-mail even if you have no connection to the Internet. The next time you establish a connection, you download all the new messages you received while disconnected and send all the mail that you wrote while disconnected. Your e-mail client allows you to add attachments to e-mail messages you send, and also lets you save attachments from messages that you receive. Attachments might include word processing documents, spreadsheets, sound files, snapshots and pieces of software. Usually, an attachment is not text (if it were, you would simply include it in the body of the message). Since e-mail messages can contain only text information, and attachments aren't text, there's a problem that needs to be solved. In the early days of e-mail, you solved this problem by hand, using a program called uuencode. The uuencode program assumes that the file contains binary information. It extracts 3 bytes from the binary file and converts them to four text characters (that is, it takes 6 bits at a time, adds 32 to the value of the 6 bits and creates a text character). What uuencode produces, therefore, is an encoded version of the original binary file that contains only text characters. In the early days of e-mail, you would run uuencode yourself and paste the uuencoded file into your e-mail message. Considering its tremendous impact on society, having forever changed the way we communicate, today's e-mail system is one of the simplest things ever devised! There are parts of the system, like the routing rules in sendmail, that get complicated, but the basic system is incredibly straightforward. The next time you send an e-mail, you'll know exactly how it's getting to its destination. Internet Safety GuidelinesInternet Safety is mostly everyday common sense applied to the tools of the internet. Here are some reminders. The only difference between internet safety and everyday safety is the tools we use. Try to practice internet safety and cyber crime prevention with the same concern, common sense and enthusiasm you have for everyday crime prevention. Be Courteous. Show respect for yourself and others in public places, including on the internet. If you received a private answer to your question or comments in a forum, chat room, or newsgroup, have the courtesy to post the response you received. Try not to use obscene or confrontational language. Remember that the person you are e-mailing or sometimes texting can't see you or the expressions on your face. So, be careful with your words and the jokes or sarcasms you write. An angry response will most likely produce another angry response. Avoid flame wars by not responding repeatedly to an angry person corresponding with you. If you are in a discussion group, forum, or chat room that is making you uncomfortable, leave and disconnect from the internet. Then, reconnect. Disconnect Yourself. Use an extension cable between your computer and modem (dial-up, wireless, broadband or satellite) so you can easily connect and disconnect the cable without harming the sensitive connectors of your computer and modem from constant use. Any computer with a connection available to the internet is susceptible to intruders and infections although your chances drastically reduce when you use firewalls, encryption, anti-virus and anti-spyware software. One alternative is to shut off your computer when you are not using it. Another alternative is to disconnect the electricity from your computer when you are not using it. However, besides being impractical, constantly disconnecting and reconnecting the electricity reduces the life of your computer's internal battery. Back-up Data. Back-up your personal files regularly just in case your computer is stolen or crashes. Use an external drive or removable media. Just as you do not carry on your person everyday all your (or your family's) credit cards, social security cards, or safe deposit box keys, don't store any personal or sensitive information (including passwords and credit card/banking information) on your computer's hard drive. Store this information on removable media or drive so it is available when you need it. Remember to store a back-up copy in a safe place. Update Regularly. Use the most recent version of installed programs. The latest version of a program typically tries to fix known problems or security vulnerabilities with the previous version. Download and install current security fixes, updates and patches for your operating system and all installed programs (not only the programs you use regularly). Be sure to download the updates from the software manufacturer's website. Downloads directly from an e-mail link (immediately downloading without being directed to the manufacturer's website) can contain infections even if the e-mail convincingly says otherwise. Vendors will send notices to opt-in subscribers through e-mail when updates are available if they offer this service. The links in these e-mails will often go to the vendor's website. They are not direct links to the download. Check and maintain safety devices – fire alarms, burglar alarms, smoke detectors, backup power supplies, anti-virus software updates, operating system and installed program security updates. Take the time to practice safety procedures: fire exits, contacting emergency personnel for possible safety compromising situations in your everyday life and with internet activities, examine e-mails and everyday situations for infectors, scams and fraud. Use Firewalls. Secure your computer. You lock your doors and windows to your home and car when you are not there. Do the same with your computer and electronic devices. Don't allow your home, car or computer to be available to strangers, intruders or thieves. Use firewalls, lock features, updated anti-virus and anti-spyware software. Be sure that both incoming and outgoing firewall protection is active. Try to maintain a separate home computer for confidential, business, and valuable information from children or persons who use file-sharing software or download "free" software regularly. You want to reduce the risk of infection and intrusion. Protect Your Kids. Keep the children's computer in the room that is most often occupied by family members with the monitor facing everyone. This helps to discourage "secret" conversations and friendships that child predators so desperately seek. This also helps adults to see where children are online, what they are doing and with whom they are communicating. Spend time as a family talking about experiences in your daily and online lives – where you went, with whom, what you did. Protect your children online as you do everyday. Don't Give Out Personal Information. Don't post your personal information at websites, guestbooks, forums, social networking communities, family homepages with or without biographical information, newsgroups, chat room profiles, text messaging profiles, or in e-mail. Your personal information includes your legal name, lastname, address, phone, marital status, occupation, passwords, logon information financial/banking/credit/insurance card information, social security numbers, and other usernames. When entering financial, banking, or credit card information online while banking or shopping, be sure the website is where you want to be and the website is secure. Look for https in the webpage address or an icon of an unbroken key or lock that is closed, glowing or golden usually at the bottom of the browser window. You can double-click the lock to display the website's certificate. Be sure this certificate matches the website you believe you are visiting. If it does not, don't enter your information. Know that some reputable websites – including stores and banks – use third-party vendor websites for financial transactions online. Check Your Energy Consumption. To be environmentally friendly as we are everyday through recycling and reducing everyday consumption of energy resources, each business and individual can contribute using resources available online. Remember also to do one of two things: either use a product such as cyberCide so your personal information is not found somewhere on the hard drive in case your computer isn't immediately destroyed or remove the hard drive and physically hammer it so the hard drive is irreversibly unusable. Be Aware of Fraud. Seniors as a group are targeted for fraud more than any other group. Predators target minors as a group more than any other group. Both seniors and minors typically have a trusting nature that can be manipulated by criminals. Be aware of offers or information you receive online in chat rooms, forums, newsgroups, websites or e-mail that could result in someone you have not met in person to visit your home or office. Be aware of someone online asking you to attend a meeting or gathering. Also be aware of supposedly a company or someone requiring your immediate online response with details of your financial, banking, credit or social security information. These are most likely scams. Prevent Computer Infections. Be aware of infections circulating in your community (such as the flu), in your e-mail, phone, text messaging programs, chat rooms and on the internet. Use preventative measures to avoid infection by using anti-virus and anti-spyware software. This will help maintain your privacy and safety. Some infectors only need you to view the e-mail in the preview pane to begin infection. Other times you do not need to click on a link in the email or an attachment. Sometimes there is no message in the text section of the e-mail. Direct your e-mail program not to automatically open e-mail attachments or display messages and pictures. This reduces the possibility of spammers verifying your e-mail address and infectors automatically installing themselves. Use anti-virus software with all incoming and outgoing e-mail. Infectors are increasingly targeting personal information. Spammers and infector authors are teaming up for a very profitable and illegal enterprise. With a phishing scam, the victim voluntarily and knowingly gives the money or property to the criminal but would not have done so if the criminal did not make a false representation or misrepresentation. Install and use more than one anti-virus software and anti-spyware software regularly. You shouldn't use these programs at the same time as it can negatively affect your computer's performance. Be sure to install updates regularly. Let the programs complement each other. Chances are if the infector or malware signature is not too prevalent or the company concentrates on one particular aspect, one company may already have included the infector signature whereas another company may not have done so yet. |