The standard port used for SMTP connections is 25. One of the most common reasons for not being able to send messages is that your Internet service provider blocks this port. This is why using an alternative SMTP port is highly recommended.

Here’s how to, depending on your OS, check whether your ISP blocks port 25:

• Check port 25 in Windows

Click on the Start menu button, usually located at the lower left corner of the screen. There is a tab called “Run”. Click it and a new window will pop up. In the text field of this window you need to type cmd and then press the “Enter” key. Another window will open. It is the so called “MS-DOS prompt” or “command prompt”. Just type the following command in the command prompt window and press “Enter”:

telnet my-domain-name.com 25

• Check port 25 in Mac OS

Each Mac OS is delivered with a preinstalled terminal emulator. The terminal is a tool which allows you to execute commands from the command line. Usually, the terminal is located under your Mac HD -> “Applications” directory -> Utilities sub-directory. When the window opens, you will see a command line with a flashing cursor on it so you can start typing right away. Just type the following command and press “Enter”:

telnet my-domain-name.com 25

• Check port 25 in Linux

Open your favorite terminal emulator and execute the following command in order to check the connection on port 25 to your website:

telnet my-domain-name.com 25

Results from the 25 port check
If the test is successful, you should receive a message similar to this one:

220-serv01.siteground173.com ESMTP Exim 4.63 #1 Wed, 18 Apr 2008 07:17:30 -0500
220-We do not authorize the use of this system to transport unsolicited,
220 and/or bulk e-mail.
If you get a message saying that the connection is refused we recommend that you use the alternative port for your SMTP connection.

What is the alternative SMTP port and how to configure an email client to use it?

The reason why most ISPs block the default SMTP port 25 is because it is used for sending unsolicited emails.

Fortunately, web hosting providers such as SiteGround offer an alternative SMTP port for the convenience of their customers.

The alternative SMTP port all SiteGround customers can use is 2525.

Information on how to change the SMTP port for the most popular mail clients can be found in our Email tutorial.

If you wish to be able to use an alternative SMTP port, as well as have unlimited mail accounts and stable mail service, you may sign up for an account at SiteGround. Our servers are using state of the art spam protection system with custom ACL filters which will ensure you will avoid the spam and at the same time never miss your important emails.

Wireless is more and more an option for businesses or even home users of computer networks. We would all like to get rid of those ugly cables and wires on the carpets or under them, on the walls or on the ceilings. Unfortunately, wireless networks are perceived as slower and not so secure as LAN networks. Over time, a series of wireless networks standards were developed, in the search for increasing security, speed and stability.

IEEE 802.11

This was the first wireless standard developed by the Institute of Electrical and Electronics Engineers (IEEE) which uses Ethernet protocol for defining WLAN (Wireless Local Area Network) standards. Transfer speeds: 6, 12 and 24 Mbits/second.

IEEE 802.11a

The improvement brought by this new standard was the transfer rate of up to 54 Mbits/second.

IEEE 802.11b

This is a simplified revision of 802.11a standard and it is the most used one, due to its low fabrication costs. The theoretical transfer rate is 11Mbits/second. It is slower than 802.11a, because it operates within the radio spectrum of 2.4 GHz, while 802.11a operates within 5GHz.

IEEE 802.11e

The improvements brought by this standard were the QoS and the multimedia support.

IEEE 802.11g

This was the answer to the challenge of combining the speed of 11a and the low costs of 11b standards. It operates on 2.4 GHz, thus fabrication costs being low as in 11a, but it offers speeds of up to 54Mbits/second, as in 11b.

IEEE 802.11n

This standard will be a big step ahead 11g standard. It will offer a speed of couple of hundreds Mbits/second, but the equipment will be more expensive. Although it hasn’t been certified, about 30,000 IT&C products complying with 802.11n have been already launched, most of them belonging to companies such as Linksys, D-Link, Netgear, Buffalo or Belkin.

Bluetooth

Bluetooth can be described as a wireless version for USB devices. It is not intended to provide high quality networking and it only works over short distances. Common uses for bluetooth include cellphone-computer communication, printing to a local printer, or PDA synchronizing.

Unfortunately bluetooth also operates on the 2.4GHz frequency potentially causing interference with your 802.11b/g network. Not to mention that using 2.4 GHz cordless phones can cause all sort of problems on 2.4 GHz networks.

Many controverses were born around the subject of wireless networks security. There are some simple steps to be followed for best WiFi security.

Also, connectivity problems were raised, due to interferences or signal interruptions. Microsoft shares with us 10 tips for improving wireless networks. Their recommendations seem to be useful for those who want to get rid of wires in their life.

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