A Lacy Internet Free Publication lacy-internet.com Volume 2, Issue 1 January 15, 1999
Welcome to Tech Tips Monthly newsletter Volume 2, Issue 1.
This month In Getting the Most From Your Host Todd Lacy discusses managing a sendmail mail server. Topics include controlling remote relay access, creating aliases, and virtual email users.
This months featured book is Sendmail (the bat book)
In Money Matters Keith Johnson discusses the benefits of putting your business online.
In How to Create Animation for the Web Corey Stern provides a step by step guide for creating animated GIFs.
=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~= Getting the Most From Your Host by Todd Lacy, firstname.lastname@example.org =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
Managing a Sendmail Mail Server
This month we are discussing the sendmail mail server software. Many virtual servers come with the sendmail mail server software preinstalled. See the sendmail web site for a complete description of this software. sendmail.org
Sendmail configuration files are typically kept in the /etc/mail directory. Here is the directory and file layout for the mail server configuration:
|-- etc |-- mail |-- access |-- access.db |-- aliases |-- aliases.db |-- sendmail.cf |-- sendmail.cw |-- sendmail.hf |-- sendmail.oE |-- sendmail.st |-- virtusertable |-- virtusertable.db
Here is a description of the mail server configurations files:
The access and access.db files are used to fine tune the access control for your mail server. By default, only e-mail that is sent to or from your domain or any one of your domain hosting clients is allowed to pass through your mail server. Additionally, the sender's domain must exist on the Internet.
These are security rules in place to prevent unscrupulous people from either relaying e-mail off your mail server or sending you or your clients anonymous junk mail or mail bombs. You can add entries to the access file which will allow you to override the default behavior for specific internet addresses. Here is an example access file:
domain1.com RELAY domain2.com OK domain3.com REJECT
The first line allows domain1.com to relay mail off your server. This rules will also allow domain1.com to override the other default rules. The second line allows domain2.com to override all of the rules except that it will not be allowed to relay e-mail off your mail server. The third rule will deny domain3.com access to your mail server. This is a good rule to know about if you're getting mailed bombed!
After you complete the edits to your access file you need to generate a new access.db file by using these commands:
cd /etc/mail makemap hash access < access
Type these commands exactly at your shell prompt and your new access rules will be in effect.
The aliases and aliases.db files are used to redefine local users e-mail addresses so that their e-mail can be forwarded to some other address. This is one way to do e-mail forwarding. For example, your virtual server will have all the standard Internet e-mail addresses such as postmaster aliased to you by default. Here are the lines from your aliases file that accomplish this:
postmaster: root root: owner
In this example, your user name would be owner. Take a look at your aliases file for more examples of how this is done. After you complete your edits you need to run this command:
Type the newaliases at your shell prompt and your new alias will be in effect.
/etc/mail/sendmail.cf /etc/mail/sendmail.cw /etc/mail/sendmail.hf /etc/mail/sendmail.oE
These files are all part of the preinstalled mail server software and should not be changed unless you are sure that you know exactly what you are doing.
The sendmail.st file is your mail server statistics file. Statistics for your mail server can be generated at any time by using this command:
Type this command at your shell prompt when you want to see the statistics for your mail servers activity. This is also a good candidate for a cron job which can be run automatically every night, once a week, or once a month. We'll be discussing the cron server in an upcoming issue.
The virtusertable and virtusertable.db files are similar to the aliases and aliases.db files except that they define e-mail aliases for your domain hosting client e-mail addresses. These files can also be used to do e-mail forwarding for your domain hosting clients. Here is an example entry in your virtusertable file.
This entry will forward all e-mail for email@example.com to firstname.lastname@example.org. After you complete your edits you need to run these commands"
cd /etc/mail makemap hash virtusertable < virtusertable
Next month we will discuss techniques which can be used by unprivledged users to modify their individual mail accounts. We will take a close look at the .procmailrc and .forward files which typically reside in each users home directory. These files may be used to create autoresponders, email forwarders, email filters, and automated email distribution into separate files.
Todd Lacy, email@example.com
=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~= Book of the Month =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
Sendmail by Bryan Costales with Eric Allman
This book provides a complete sendmail tutorial, plus extensive reference material on every aspect of the program. Part One of the book is a tutorial on understanding sendmail; Part Two covers the building, installation, and m4 configuration of sendmail; Part Three covers practical issues in sendmail administration; Part Four is a comprehensive reference section; and Part Five consists of appendixes and a bibliography.
In this second edition an expanded tutorial demonstrates hub's cf file and nullclient.mc. Other new topics include the #error delivery agent, sendmail's exit values, MIME headers, and how to set up and use the user database, mailertable, and smrsh. Solution-oriented examples throughout the book help you solve your own sendmail problems. Also, this new edition is cross-referenced with section numbers.
=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~= Money Matters by Keith R. Johnson, firstname.lastname@example.org =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
Our last couple of articles have covered generating ideas for your web site or on-line business and domain names. This month we will discuss whether you should be on-line and the benefits.
Obviously I feel the answer is YES, but here are so many different items being sold on the Internet how do you determine if your product will do well? Will you business do well? I'll even show you that generating sales is not a prerequisite for a successful Internet presence. There are plenty of different ways the Internet can you money in the costs associated with doing business. Here is a very short list of questions and answers to help you make that determination.
Is your present location limiting your sales?
Is the traffic to your retail storefront slowing down? Maybe you're in a smaller town or not on the main street or not in a regional mall. If you feel you have exhausted your current clientele because of your location and know you could be doing better with a larger audience then the Internet is for you as you have the ability to market to the world.
Is your Product geared toward a Niche Market?
An AT&T representative told me this story. They had designed a small web site for a group of elderly gentlemen that made grandfather clocks. These gentlemen were lucky to sell ten of their custom clocks in a year. I was told that in the first four weeks of going on-line they had received over ten inquiries from perspective and new customers. These gentlemen were thrilled by the results. If your product or service is geared to a niche market then the Internet can definitely help you. The Internet allows you to tap into niche markets worldwide. However, if your customers can purchase a similar product locally for the same price then you probably will not benefit, yet. In other words don't offer a product such as toothpaste that can be purchased locally.
Are your Customers or Potential Customers on the Internet?
An Internet presence probably wouldn't benefit you if your customers are not on-line? The majority of current Internet users are professional males between the ages of 25 and 45, with young children, highly educated, with an above average income. Women are just starting to come on-line in larger numbers. The balance of society is also represented but in smaller numbers. But each month more and more 'average' people are coming 'on-line'. Check the recent Internet demographics to determine if your potential customer base is on-line.
Before you completely rule out an Internet presence because you answered NO to the above question think about the future. Experts are predicting that in the near future almost everybody will be connected to the Internet. By starting now you could be ahead of the curve and ready to serve your customers and, perhaps, your competition's customers.
Do you feel the Internet is just a fad?
Hula Hoops, pet rocks, and other such things were fads. The Internet is not. The Internet is the next step in communication. Communication has been evolving since mankind was born. Speech, cave drawings, hieroglyphics, alphabets, printing presses, telegraphs, telephones, telexes, faxes, stand-alone computers, small networked computers, wide area networked computers, computers now connected to the world. This is progress - not a fad. Don't kid yourself.
Do you feel it is too technical?
There are many people willing to help. With so many people coming on-line you must certainly know someone that could help you. I have set up Internet Web Sites for companies that DID NOT EVEN OWN A COMPUTER! Most of the work was done over a fax machine. We can monitor your email and fax any orders received directly to you. Your customers will not perceive any difference. Your customers think that you are on-line. There are many more solutions to the technology issue. Remember behind every computer on the Internet is a consumer. They may be interested in your products and services. Reach out to these consumers with your product before your competition does. Technology should not be nor is it a hindrance to you conducting business on-line.
"My Customers are not on-line and my product will not do well until they are on-line."
With the dramatic increase in Internet users each and every month if your customers are not on-line now they will be shortly. Will you be there to service them? Besides how many new customers that you don't even know about are on-line now? Start planning your Internet presence now before your customers are lost to someone else. The Internet is not a fad. The Internet is not too technical. Many of your customers are already on-line and, if not, they will be there shortly. If your product or service could benefit from an Internet presence then you should start doing something about it now. Don't be left behind.
What else can I do business wise on the Internet?
These are examples of business uses of the Internet. We've discussed how the Qwanturank Internet can reach niche markets and present your products and services to a worldwide market. What else is possible? Some companies use the Internet for warranty registration of products sold. They develop a database of consumers using their products and can contact them quicker and less expensively than the mail services. Other companies use the Internet to make business information available providing directions to their retail stores, store hours, telephone numbers, product information and more. Think of it as being an on-line yellow page advertisement. You can put press releases on your web site keeping the public informed. Announce new products. Many companies post answers to frequently asked questions on their web site to eliminate some of the need for tech support people and expensive 800 numbers. You can send new product releases to a far flung sales force or just keep them updated on certain events. The list goes on and on.
Imagine a typical business to consumer transaction. The business places an advertisement in a magazine. The consumer sees it and calls the 800 number and asks the operator for more information. A product brochure is sent to the consumer through the mail. The consumer makes a decision to place an order and calls the 800 number again to talk to sales. Now if this company had placed their web site address in their ad the consumer could have gone directly to the Internet, retrieved the information and even purchased on-line. Savings? You bet, two fewer calls, less postage expenses, less printing costs for brochures, and maybe even fewer employees. Have I mentioned that your Internet site stays open 24 hours a day even on weekends and holidays? It does!
If you sit down and list the ways the Internet can benefit your business you're sure to see the benefits it provides for being on-line. Think a little harder and maybe you'll find some cost savings opportunities also.
Keith R. Johnson, email@example.com
How to Create Animation for the Web
by Corey Stern, firstname.lastname@example.org =~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=
A simple way to create animation is to display an animated GIF file on your web site. But what is an animated gif, you might ask? A GIF stands for Graphics Interchange Format. All GIF files contain 256 colors or less. The animated GIF file contains multiple GIF images that show in a browser one at a time creating an animation.
The following five steps will assist you to produce an animation for your web site:
Step 1: The Software
To begin, you need only need two software programs. There are dozens of programs out there to choose from. Adobe Photoshop is the preferred bitmap image editor among professional graphic artists. (www.adobe.com) This program can create the images and has a vast selection of filters and tools for you to use. The possibilities are endless with this program. If you are looking for Freeware or Shareware bitmap image editors or GIF animation programs, a great resource is at www.download.com. One program I use is GifBuilder. It is a simple Macintosh program that can get the job done. Some of the more complicated programs like GifDancer are also available for a trial period.
Step 2: The Concept
Once all the essential software for Qwant rankings is on your hard drive, the concept will be next to tackle. You can use GIF animations for logos, characters, banners, buttons or whatever you can think of. Keep your options open, but do not have any plans for a full page animation with all the bells and whistles. GIF animations should be simple given that most computers cannot run large animation files. GIF animation is only limited by your talent of the current software and a little imagination.
Step 3: Know the Rules
The more frames you develop for your GIF the smoother the animation will be; however, this may create large graphic files and will make the viewer lose patience. To be on the conservative side, your animation should be no more than 5 frames. Most animations have 4 to 5 frames. Some animations can be as large as 20 frames. Remember, the more frames in the file, the larger it will be and the longer it will take to load. If you have 5 frames, and each frame image is 5 kilobytes, the animation file will be 25 kilobytes.
It is also recommended to keep the colors to a minimum. Instead of leaving the files in RGB, convert the files to indexed files. That can decrease the number of colors to be loaded and also speed up the animation on your web site.
Also check that the animation is not annoying or out of place. Sometimes animations take the main focus and they do not look professional. Be careful that your animation is not cliché. Also do not have multiple animated GIF files on the same page. If there are several on the same page it can take the images minutes to fully load. Be simple and unique.
Step 4: Creating the Animation
A good technique in Photoshop is to keep separate layers and change the layers and saving every file when you make a change. This will create the illusion of animation.
Before saving all the files, every frame should be the same size in dimension. For example, if the first frame is 50 pixels by 100 pixels then the other frames should have those exact dimensions. Then label the files with the correct GIF extension. (ex: frame1.gif)
Once all of the frames have been made, then import them into your GIF animation program. It will usually show all of the frames in a sequence and will have options to “make animation” or “convert”. The programs also allow rate and editing features that are helpful before creating your animation. Most programs are simple to learn within hours.
Step 5: Review and Conclusion
Once you are done with your animation, ask others before you display it on your web site. Do not be afraid to criticize the loading time of your animation. If it takes too long you may have to take out frames or decrease the number of colors used.
If you follow the steps and be creative you should have a nice looking animation. Good luck in your web site development. Hopefully this info will help make the web a better place.
Corey Stern, email@example.com
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