beginning Ubuntu Linux phần 6 docx

Click Edit Preferences, ensure that the Mail Accounts icon is selected on the leftside of the window, and select your mail account in the list on the right side of thewindow.. If you wan

Figure 14-1 You can switch between Evolution’s modes by clicking the buttons at the bottom left of the

program window

Mail

Contacts

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Note Although e-mail is normally sent as soon as you click the Send button after composing it, if the sending

has been delayed for any reason (such as being offline at the time), it will take place as soon as you click the Send/Receive button Until that point, it will be held in the Outbox folder on the left side of the program window You may need to choose File Work Online if you’ve been composing e-mail in offline mode

Figure 14-3 You’ll see a progress bar display whenever you click the Send/Receive button

E-MAIL SIGNING AND ENCRYPTION

In Chapter 8, you learned how to use the Seahorse application to set up a public key pair This allows you

to encrypt e-mail messages destined for other people, so that only they can read the messages (providedyou have their public key) The application also enables you to digitally sign your own e-mail, so recipients

can be sure messages came from you (provided they have your public key) If you’ve followed the

instructions to set up the key pair, and uploaded it to a key server, you now need to configure Evolution touse it After doing this, and when you send a new e-mail message, you can select whether you wish toencrypt the e-mail and/or digitally sign it

Remember that setting up encryption is not obligatory, and relatively few people in the wider world use

e-mail encryption or signing

Assuming you’ve already set up an account within Evolution, here’s the procedure for configuring Evolutionfor encryption and digital signing:

1 Click Edit Preferences, ensure that the Mail Accounts icon is selected on the leftside of the window, and select your mail account in the list on the right side of thewindow Then click the Edit button In the dialog box that appears, click theSecurity tab

2 You now need to find your PGP key ID by using Seahorse Click Applications Accessories Passwords and Encryption Keys Locate your key in the list underthe My Personal Keys tab, and look under the Key ID heading You should see aneight-character hexadecimal number, like F0C1B52A Write this down,

remembering that any 0 you see is a zero, not the letter O

3 Switch back to the Evolution dialog box and type the PGP key ID you found into thePGP/GPG Key ID box If you want every e-mail message you send to be digitally

signed automatically, which is a good idea (the message itself won’t be encrypted,

so even if the recipients are not using encryption, they will still be able to read it),ensure there’s a check in the Always Sign Outgoing Messages When Using ThisAccount box Then click OK and close the parent Preferences dialog box

to encrypt a message addressed to that person, or you’ll see an error If you sign a message, upon sending

it, you’ll be prompted to enter the PGP passphrase you entered when you created the key pair back in

Chapter 8

If, upon sending an e-mail message, you see the error message “Failed to execute GPG: Broken pipe,” it’s likely you mistyped your key ID when you configured Evolution Try again

If you receive a message that has been encrypted using your public key, Evolution will automatically

prompt you to enter your PGP passphrase to decrypt it This is the passphrase you entered when creating your key pair back in Chapter 8

When you receive a message from someone who uses digital signing, and you have that person’s public

key, the message should contain a green bar along the bottom containing the words Valid signature If you

see words to the effect that the signature is invalid, or if the signature is missing, you should be suspicious and independently verify the authenticity of the e-mail message

Figure 14-4 To permanently delete messages, right-click the Trash folder and select Empty Trash

Earlier in the book, we discussed a method of exporting e-mail from various Microsoft e-mail programs, which use proprietary formats, so that it can be imported under Ubuntu To recap, you can install the

Mozilla Thunderbird e-mail client under Windows, import your e-mail into it from Outlook or Outlook

Express, and then export Thunderbird’s mailbox (.mbox) files for importing within Evolution

If you followed these instructions and now have the mbox files ready for use with Evolution, it’s easy to import them Click File Import In the Import dialog box, click the Forward button and then select Import

a Single File Click Forward again and click the Filename drop-down list This will open a file-browsing dialog box, in which you can locate the mbox file and click Open If you have more than one mbox file, you’ll need to import each one manually The Automatic entry in the dialog box refers to the file type and will select the correct file type by file extension

Figure 14-5 New messages can be formatted in HTML, allowing you to format text and even add images to

your messages

Tip Many people in the Linux community frown on HTML-formatted e-mail and prefer plain text messages

Note The aspell-fr package also includes the Swiss French variation of the language

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Advanced E-Mail Tasks

Figure 14-7 You can create your own folders to better organize your mail

Note The junk mail filter used in Evolution is a third-party program called Bogofilter (http://bogofilter sourceforge.net) You can switch Evolution to an alternative spam filter, which some consider more powerful, called SpamAssassin (http://spamassassin.apache.org) To do so, install the spamassassin package Restart Evolution, click Edit Preferences, click the Mail Preferences icon in the dialog box that appears, and click the Junk tab Then select SpamAssassin from the Default Junk Plugin drop-down list While on that preferences page, it’s also a good idea to select the Do Not Mark Messages As Junk If Sender Is In My Address Book check box When you are finished, click OK and then Close to return to the main Evolution program window

Tip Several If rules can be created For example, you could create a rule to filter by the address of the sender,

and then click the Add Condition button to create another rule to filter by text in the Subject line If you click If All Conditions Are Met in the Find Items drop-down list, the mail will be filtered only if both conditions are met If you click If Any Conditions Are Met from the drop-down list, the mail will be filtered if either condition is met

Figure 14-8 Creating message filters lets you automatically organize your e-mail as soon as it’s received

TIPS FOR USING EVOLUTION E-MAIL

In many ways, Evolution is similar to e-mail programs you might have used in the past, but it also has a few of its own quirks and idiosyncratic ways of working Here are a handful of preferences you might want

to set to have Evolution behave in a more familiar way:

• Forward e-mail inline: If you attempt to forward a message, Evolution will attach it

to a new message as a file The person receiving the e-mail will then need to

double-click the file to view the forwarded e-mail, which can be confusing The

solution is to make Evolution forward the message inline, which is to say that

Evolution will quote it beneath the new mail message, like Microsoft e-mail

programs To do this, click Edit Preferences, click Composer Preferences on the

left side of the dialog box, click the Forward Style drop-down list, and select Inline

• Change the plain text font: Any messages sent to you in plain text format, rather

than HTML, will appear in the message preview pane in a Courier-style font To

have messages display in a more attractive and readable typeface, click Edit Preferences, select Mail Preferences on the left side of the dialog box, and thenremove the check from Use the Same Fonts As Other Applications In the FixedWidth Font drop-down list, select an alternative font The standard Ubuntu font iscalled Sans and is a good choice

• Always create HTML e-mail: Evolution defaults to plain text e-mail for any new

messages you create If you want to always create HTML messages, click Edit Preferences, click Composer Preferences on the left side of the dialog box, andthen put a check alongside Format Messages in HTML

• Empty trash on exit: To automatically get rid of deleted messages each time you

quit Evolution, click Edit Preferences, click Mail Preferences on the left side ofthe dialog box, and put a check alongside Empty Wastebasket Folders on Exit.Then select how often you would like this to happen from the drop-down list:every time you quit Evolution, once per day, once per week, or once per month

• Vertical message window: As an alternative to positioning the message preview

window beneath your messages, Outlook lets you position the message at theright of the message list, thus forming three vertical columns (folders, messages,and preview) To switch to this view under Evolution, click View Preview Vertical View

Figure 14-9 A lot of information can be entered for each contact, and, by clicking the button at the top left,

you can also add a photograph

Note A vCard is a virtual business card Effectively, it’s a small file that contains personal information vCards

can also contain pictures and audio clips They’re understood by practically all business-level e-mail programs, including Microsoft Outlook and Apple OS X’s Mail program

Calendars

Appointments

All-day appointments

Meetings

Note When you right-click in Calendars mode, you’ll also see an option to add a task Adding a task in

Calendars mode automatically links it to the selected day and time Task items due on the current day are marked

in dark blue

Figure 14-10 When creating a new appointment, you can add all the details you need, but don’t forget to

set how long it lasts!

Additional Calendars

Figure 14-11 Evolution can manage both local calendars and remote calendars from the Internet, making

it ideal for creating and sharing group calendars

Memos and Tasks

Note Memos created in Evolution can also be opened in Tomboy, the default GNOME desktop note-taking

application

Figure 14-12 Tasks mode lets you catalog chores that you want to do during the day

Configuring Instant Messaging

chat accounts)

Figure 14-13 Empathy can communicate with users across a range of different protocols

Table 14-1 Instant Messaging Services That Can Be Used with Empathy

Instant Messaging

Service Description

I seek you

Installing Skype

deb http://download.skype.com/linux/repos/debian/ stable non-free

Figure 14-14 It’s easy to install Skype under Ubuntu, and it works almost exactly as it does under

Windows or Macintosh

Tip To configure your audio input device (e.g., microphone), right-click the Speaker icon at the top right of the

desktop and select Open Volume Control Then click and drag the Microphone slider as necessary You may need

to unmute the input by removing the red cross next to the speaker icon below the Microphone slider

Ekiga

Figure 14-15 Ekiga is an open source alternative to Skype

Summary

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Social Networks

and Cloud Computing

From the very beginning, computer networks were about more than just connecting devices They were about connecting people

The day two computers first got connected, a communication path between two human beings was formed As the number of connections increased, more and more people were sharing information,

experiences, and their lives Today, of course, we have the web With its ubiquity, the possibilities are

bounded only by our collective imagination

Social networks have emerged to harness the commincation power of the web You want to get back

in touch with your old classmates from high school? Check You want to create a virtual business card

and relate to colleagues? Check You want to publish your activities so people know what you are doing all the time? Check

However, administering your online persona can be an overwhelming task Social networking

sites are currently self-centered and poorly, if at all, integrated, so you have to check and update them

one by one

What we need are applications that do the heavy work for us and let us concentrate on what we

want to publish and where—not on how to do it

A second web trend has emerged: so-called cloud computing As the processing power and storage

capacity of the Internet as a whole rises exponentially, so do the benefits of running applications and

saving data online, rather than doing so on your own PC We are in the middle of a computing revolution

in which the core processing unit is no longer the individual PC, but the “cloud” of connected devices Today, more and more sites provide free space to store personal information in the cloud, whether

in order to share with others (for example, a photo in an album you create), or just to have an online

copy of your private data

In this chapter, we talk about how Ubuntu can leverage those two trends and make our online life a lot easier and pleasant

■ Note One of the main applications you will be using with social networks and cloud-based services is your

favorite web browser Most browsers that you can use with Ubuntu are very well suited for social networking In this chapter we talk about other applications that connect directly to the Internet to perform specific tasks, using its resources as if they were local to your PC

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Social Networking Applications

In the last few years, the use of social networks has experienced staggering growth Sites like Twitter and Facebook serve millions of users per day and generate terabytes of data

WELCOME TO WEB 2.0

Social network sites are part of a greater movement called web 2.0

The “first” Internet (web 1.0) offered us mainly static content, provided by the site owner The user

consumed that content typically by using a web browser Web 1.0 sites included newspapers, magazines, and corporate or e-commerce sites The user could read the pages, buy something online, and if the site allowed she could post a comment to an existing web page The user was strictly a consumer

Web 2.0, on the other hand, is a platform to share—to share interests, photos, video, status, and any other

information that we deem interesting There is no “main publisher,” and when there is a centralized

authority, its role is mainly to set the rules and enforce them, not to produce content Think YouTube,

Wikipedia, Twitter, and Facebook

Several types of sites are considered part of the “Web 2.0,” including but not limited to:

• Wikis: These are sites that allow users to create content in the form of sets of

interrelated web pages, often with a common subject It is well suited for documentation of specific topics and for encyclopedias, the most famous being Wikipedia

• Blogs: A blog (short for web log) is a service that allows a user or set of users to

post content, forming a web page of continuous posts sorted in chronological order (showing the newest post first) Derivations of the original blog concept are photoblogs and Microblogging sites (which set a size limit for posts)

• Social networks: These are sites that allow users to create profiles and connect to

other users to share information and interests Those connected users are typically

called friends The content shared is often divided into private and public content,

private content being available only through authorized connections

Ubuntu 10.04 was designed to be “social from the start,” which means that it integrates with social networks seamlessly In the first section of this chapter we look at some of the applications you can use for this purpose

Introducing the MeMenu

Lucid Lynx includes a new applet located in the top panel, next to the Date and the Shutdown button, as

is shown in Figure 15-1 It is the MeMenu, and it was so important for the developing team that its interface was sketched by Mike Shuttleworth himself The MeMenu is the cornerstone of a strategy to make you feel like there is no real difference between your local account and your online persona; they are one and the same Once you log in to Ubuntu, you are online!

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of accounts

Figure 15-1 The MeMenu allows you to set IM status and to broadcast to your social networks

Title: The Title section includes an icon representing the online status of your IM accounts, and your

short name as specified in About Me (see Chapter 9) It could be that your multiple Chat accounts

will have different statuses; in that case, the icon appears as a thick dash—or as disabled if no Chat account has been created

Me: The Me section contains a photo and your full name, as specified in About Me

Broadcast: The Broadcast section consists of a text box It is shown only if you have created at least

one Broadcast account You can enter text in the box, and it’s posted to all checked Broadcast

accounts the moment you press Enter Be aware that some social networks limit the number of

characters of your posts (Twitter’s tweets are limited to 140 characters; Facebook status updates can run to 420 characters)

IM Status: The IM Status section lets you set the status for multiple Chat accounts You have several

options: Available, Away, Busy, Invisible, and Offline Selecting one option sets all Chat accounts to that status

Account Configuration: The Account Configuration section lets you associate your online accounts

with your profile You can create both Chat accounts and Broadcast accounts There’s also a pointer

to Ubuntu One, a cloud-based storage service about which we will talk later in this Chapter

The MeMenu relies on Empathy (already seen in Chapter 14) for Chat accounts and on Gwibber

(more about it later) for Broadcast accounts Those applications should be installed if you want to create accounts of each type

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Microblogging with Gwibber

Gwibber is a microblogging client for the GNOME desktop environment that you can use to access Twitter, Facebook, and other social networking sites

Microblogging is a complex cultural phenomenon, but in itself consists of only two basic operations:

to post content, and to read other users’ posts (called following, as on Twitter) It is the aggregation of

millions of such operations a day that renders microblogging so interesting

As the number of social network sites continues to grow, it is hard for users to keep up the pace

We want our posts to have the greatest impact, so we need to send it to every single microblogging site available, just to make sure no one misses it On the other hand, we want to receive the most

relevant content, no matter where it was originally posted We can’t stick to a single service, we must use them all

Without tools that help us with these tasks, to fulfill that simple objective we would have to update every site manually, using a web browser, and then check them one by one to see if there is some interesting stuff We would rarely have time to do this

Someone once said: “I will work 24 hours a day, and nights too.” That sentiment also seems to apply

to social networking

Here’s where Gwibber comes in It allows you to post to multiple sites at the same time, and follow content from different sources Whereas the MeMenu can post short messages to some microblogging sites, Gwibber lets you also read other people’s threads

Gwibber is installed by default and can be found at Applications  Internet as Gwibber Social Client If for some reason you don’t have it, you can install it by going to Applications  Ubuntu

Software Center Click Get Free Software in the left pane and select the category Internet Browse the list

of available applications and select Gwibber Click Install to begin installation (refer to Chapter 20 for further information on how to install or remove software)

The basic interface, as shown in Figure 15-2, is quite simple

Figure 15-2 Gwibber lets you configure multiple social networking sites

At the top is a menu that contains only three entries: Gwibber, Edit, and Help

The main section is divided into two panes: the Streams pane, where you can see your mailboxes, and the Details pane, where the selected mailbox actual posts are shown