Articles

In the terms of web hosting SSL certificates are used for identification of the end-website (e.g. for fishing protection purposes) and for encryption of transferred data (login info, passwords, credit cards numbers and other private information).

Organization issuing certificates is called Certificate Authority. It checks the following credentials depending on ordered verification level:

1. Domain name
2. Domain name and business details
3. Domain name, business details and personality of organization representative. It is called extended validation.

The higher security level of certificate – the higher website trust level.

Usually certificates are issued for the particular domain name (e.g. example.com).There is a strict match. Sub-domains (e.g. shop.example.com) require separate certificates with the corresponding names.

If required you can use special certificates for several domain names (e.g. wildcard SSL certificate) or multi-domain certificate. (more…)

This article goes over some of the common reasons why e-mail that is sent from your server would be marked as SPAM by Internet Service Providers, and ways to prevent it.

As the anti-SPAM methods and technologies become more and more complicated, so must the measures being taken to avoid having email sent from your server also marked as SPAM. Popular email providers such as Gmail, Yahoo and Hotmail, as well as most major Internet Service Providers, have specific requirements for mail servers that attempting to send mail to them.

There are several reasons for mail sent from your server being marked as SPAM, which include:

• Reverse DNS and mail server hostname entries do not match. If you changed your hostname, this could be the case. Having a Reverse DNS entry which corresponds to the primary IP address of your server can greatly help in reducing the chance of your messages being marked as SPAM. You should contact the owner of your network block (in a most typical case, this will be a datacenter support department) to correct the reverse DNS entry.
• Your mail server may be on the SPAM blocking list (DNSBL). DNSBLs are most often used to publish the addresses of computers or networks linked to spamming; most mail server software can be configured to reject or flag messages which have been sent from a site listed on one or more such lists. You can check the main IP address of your server against the most widely used blacklists by the following addresses: http://checker.msrbl.com/ or http://rbls.org/ . There will be links to all of the Blacklists, and if for some reason your server has been added, there are usually explanations on their sites of how to remove yourself. (more…)

Most of abusing SPAM mails nowadays have forgot sender addresses. This may cause further complications (in both reputation loss and flood of bounced messages from fake messages delivered to your mailbox) if your own email address is used as spam origin. Offender doesn’t need to have access to your mail service in order to send his own messages with fake envelope sender address. Unfortunately SMTP protocol doesn’t have any protection mechanism to prevent mail sender forgery, so this is where SPF comes to play.

Basically SPF (Sender Policy Framework) is an standard used for determining if mail message was sent by its genuine sender. All you need in order to implement SPF for your domain is to create special TXT record in your DNS zone. You could contact your domain registrar or hosting provider, if you are using its nameservers, for managing DNS zone for your domain if you don’t have direct access to it.

Let’s check this record syntax on the following example:

example.org. TXT “v=spf1 mx a:special.example.org ~all” (more…)

In the Internet the standard protocol for sending emails is SMTP. This protocol also deals with delivery errors, that could occur because of different reasons. And a bounce message in SMTP means an automated message from a mail system informing the sender of another message about a delivery problem and the reasons that caused it.

Below is an example of a bounce message:

Hi. This is the qmail-send program at example.com.

I’m afraid I wasn’t able to deliver your message to the following addresses.

This is a permanent error; I’ve given up. Sorry it didn’t work out.

<somewhere@example.com>:

10.10.10.10. does not like recipient.

Remote host said: 550 MAILBOX NOT FOUND

Giving up on 10.10.10.10.

The messages “MAILBOX NOT FOUND” or “User unknown” are key and might actually be any of several different messages depending on the reason for the failure: (more…)

Problem description
You have problems with opening your site, accessing mail or database server. You have contacted hosting support and they asked for one\several commands output. But you have no idea how to Run them.

Resolution
Windows
On any NT-based windows version cmd.exe program is used as command mode interpreter. You can start it in one of the following ways:

• by opening “Start => All Programs => Accessories => Command Prompt”
• by opening “Start => Run” , entering ‘cmd’ and clicking “Ok” (there is no “Run” menu element since windows Vista but you can open “Run” dialogue by pressing Windows key+R)

Now you have windows cmd.exe opened and you can run needed commands. Note only that common keys combination like Ctrl+C for copy or Ctrl+V for paste will not work in Windows cmd. You will have to use context menu opened by clicking right mouse key on cmd window.

• click on ‘Mark’ to mark text you are going to copy
• hit Enter key to copy marked text
• click ‘Paste’ to paste copied text to command prompt

MacOS\Linux
You can access terminal/shell application used as command mode interpreter on MacOS by clicking on ‘Terminal’ element in “Applications->Utilities” menu. Almost the same steps can be used to open Terminal application on Linux, difference can be only in path to ‘Terminal’ element in Main menu, depending on Desktop environment used on your computer (KDE, Gnome, etc.) Keys combination like Ctrl+C for copy or Ctrl+V for paste will work in MacOS/Linux terminal. (more…)

500 “Internal Server Error” is a very generic error message. It means that something went wrong on the web server. It is displayed if server can not identify exactly the essence of the problem.

The most common reasons are:

1. errors in your script
2. incorrect or not supported instructions in .htaccess file

There are also other possible reasons of error 500, however they hardly ever arise.

Solution

Checking web server’s error log is the best way to find the reason for the problem. Usually customers do not have access to error log on hosting servers therefore you should contact your host support (place a ticket, call phone support, etc.) and ask them to look up error message from their side.

Case I

First lets discuss the case of incorrect instruction in .htaccess file. In this case support will find error message similar to the following one in web server error log:

[Wed Apr 28 3:01:38 2010] [alert] [client 123.123.123.123]

/home/XXXXX/vstest.com/public_html/.htaccess: Invalid command

‘DirectoriIndex’, perhaps mis-spelled or defined by a module not

included in the server configuration

As you can see webserver returned instruction name it considers wrong (or unknown as in this particular case). There is no ‘DirectoriIndex’ directive, it is a typo. Correct directory name is ‘DirectoryIndex’. So you should just correct the typo in .htaccess

Case II

If error 500 appeared on request to some script (.php, .pl, .cgi, etc.) you should check file system permissions for that script. Permissions should be set to 644 (rw-r–r–). If permissions are not correct you should change them by using chmod command in unix shell, or use FTP or FileManager in CPanel.

(more…)

Awstats is a web log analysis and reporting tool. Awstats makes its reports using web server access logs as a subject to analyze. Reports made by awstats are usually useful to determine the following:

• success of the last advertizing campaign
• unique visits your website served
• progress of your web traffic
• keywords used to locate your website through web search engines (i.e. google.com etc.)

(more…)

Bandwidth is the amount of traffic used by your account. cPanel tracks all activity, including web traffic (usually largest part of all bandwidth usage), FTP activity and email.

HTTP (or Hypertext Transfer Protocol) is a protocol designed for distribution of different web-pages. Usually it is simply called web traffic. Web traffic is generated by site visitors. Amount of web traffic depends on number of visitors. It means that small web page can generate a lot of traffic if there is a lot of visitors.

File Transfer Protocol (FTP) is a standard network protocol used to copy a file from one host to another over a network, such as the Internet. It is usually used to upload files to the hosting server. If you upload a lot of data, the traffic amount will be quite large.

POP3, SMTP, IMAP are the protocols used for receiving or sendind emails. If you send or recieve lots of email every day this could also become a large part of your total bandwidth.

(more…)