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Webspace: How to run Auto-SSL manually

A free SSL certificate for your domain can be installed at any time within cPanel. Your website will receive automatically a free SSL certificate after 12-24 hours, however requesting the certificate manually will install it immediately.

In case your browser shows the following warning when accessing your website via https:// the SSL certificate might not be installed yet.

In order to request the certificate manually you need to login to your cPanel account, the login information was sent to you via E-Mail before.

Once logged in you need to navigate to "SSL/TLS Status".
Afterwards select the checkbox of the domain you would like to secure and hit "Run AutoSSL".

Important: In case of an error you further need to investigate the reason. A certain amount of failed SSL requests will get your domain suspended from Let's Encrypt Auto-SSL, the suspension might last several days or even weeks.
The following request failed as the DNS was not updated yet. It might take up to 24-48 hours in case your domain is being transferred. Recently (newly) created domains might take several hours to work properly.

In our case the subdomain was missing in DNS-Management, we added a corresponding entry and waited a couple of minutes (one cup of coffee).

We rescheduled AutoSSL to run immediately and it properly installed the certificate:

The website is accessible via https:// and no browser warning will be displayed.

In order to redirect any non secured "http://" to secured/encrypted "https://" traffic you might want to add a corresponding .htaccess redirect rule or alternatively add a rule within cPanels "Redirect" menu:

A common issue after securing your website is the so called "mixed content", in case you are using static .html files you need to update any http:// reference to https:// manually.
The browser's "lock" icon will appear green afterwards.

In case you have any issues with Auto-SSL feel free to contact our customer support via E-Mail. Please make sure to wait at least 24 hours, in case your domain is still being transferred.

Posted by: Gianni-Donato | Tagged as: , , , , , No Comments

Data center uplinks: 200 Gbit/s at Contabo now!

Constant readers of our blog and our existing customers now it already: We are continuously working on improvements! This involves not just our regular systems, but also our infrastructure - in this special case our data center connectivity:

Recently, we have increased it by an additional 70 Gbit/s. Now we are connected to the Internet with 200 Gbit/s!

The following uplinks are available right now:

  • CenturyLink: 60 Gbit/s
  • Telia Carrier: 60 Gbit/s
  • Versatel: 20 Gbit/s
  • DE-CIX: 20 Gbit/s
  • AMS-IX: 20 Gbit/s
  • M-NET: 10 Gbit/s
  • Colt: 10 Gbit/s

Our goal is to offer you an even better redundancy, to increase the available bandwidth and to provide a great global routing.

You can count on us: In the future, we will improve our uplinks even further - for you, our valued customers!

You can find additional information about our data centers on our website!


Contabo customer survey 2019

We have repeated our customer survey 2018 this year and once again asked you, our existing customers, to answer a few questions about us and our services. Just like last year, the participation was outstanding. In just a couple of days, more than 9000 customers took part and we would like to thank all of you for doing so! Your estimation and comments are a valuable feedback for us in order to further improve our services.

We are happy to announce that 95% of you are very satisfied or satisfied with our services. Compared to last year's survey, we managed to increase this number by one percent. By the way, the same accounts for the recommendation ratio 🙂 We are very excited about this result; at the same time, we would like to assure you that we will evaluate your remarks and recommendations. After all, it is our goal to provide you with services that meet your expectations - true to our motto "The customer is king".

Again, we have raffled 3 x 100 Euro among all participants and the happy winners are:

  • Pedro R. from Queluz (Portugal)
  • Esben F. from Esbjerg (Denmark)
  • Thomas W. from Neusitz (Germany)

Congratulations! The prizes were credited to the respective customer accounts as a credit note, which can be used to pay for the upcoming renewal of the registered services with us.

Posted by: Markus | Tagged as: , , , , 6 Comments

Establishing a connection to your server via SSH

In this tutorial you will find a guide on how to establish a connection via SSH to your Linux server.

Please note that you will have to replace the place holder <IP Address> in the complete tutorial with the IP address of your server.


In case you are using a Linux operating system on your local machine you will just have to start a terminal.

To establish the connection to your server please type the following command:

The option -l defines the user which will be connected to. In this case we will use "root".
The option -p defines the port which will be used for the connection. Here we will use the standard SSH port 22.

Should this be the first time you connect to the server, you will have to accept its SSH certificate by typing "yes".

Please insert your password, which you can find in our e-mail "Your Login Data". Kindly note that SSH will not display any letters or symbols when typing the password. You can also copy and paste your password by using the right mouse key (please make sure not to copy your password with blank characters at the end - you can check so by pasting the password into an empty editor file before using it).

Now, click the ‚Enter‘-key. Once done, you should get access to your server via SSH:

The connection has now been established successfully.


In case you are using a Windows operating system on your local machine, you will have to install a suitable SSH client first.

We recommend to use PuTTy as SSH client:


After installing PuTTy, open the client and enter the IP address of your Server. The port, in this case the standard SSH port 22, can be changed as well if needed.

Click 'Open' to initiate the connection. You can leave all options to default.

Should this be the first time to connect to the server, you will have to accept its SSH certificate:

Afterwards, you will see the following:

Please insert root (login as:) and your password, which you can find in our e-mail "Your Login Data". Kindly note, SSH will not display any letters or symbols when typing the password. You can also copy and paste your password by using the right mouse key (please make sure not to copy your password with blank characters at the end - you can check so by pasting the password into an empty editor file before using it).

Now, click the ‚Enter‘-key. Once done, you should get access to your server via SSH:

The connection has now been established successfully.

Posted by: Julian | Tagged as: , , , , , , No Comments

Special offer: Dedicated Server 10-Core one month for free!

Here in Germany, the temperatures are heating up once again towards the end of summer - reason enough for us to join the party and offer you something special: As of now and for a limited time only, you can get our brand new Dedicated Server 10-Core one month for free!
The Dedicated Server is equipped with state-of-the-art hardware from Intel, namely the Xeon E5 2630v4 processor with 10 x 2.2 Ghz and 256 GB RAM!

Simply place your order and you will get the server free of charge for the first month. However, in order to complete your purchase it is mandatory to send us the initial payment, with the amount depending on your selected contract length. Only then we can install your new and powerful Dedicated Server. We will launch the installation of your server as soon as we receive your payment, and of course no additional setup fee is charged by us!

At this point we are certainly not done yet! You may also benefit from our second promotion and get a refund of up to another monthly fee, depending on your selected contract length. For example, if you go for a 12 month contract, you will have to pay just 11 months. Please note: Your contract starts after the free month, which means that your payment for 11 months covers a time span of 13 months!

Sounds good to you? Please click here for an overview of our Dedicated Servers!


Webhostlist: First place for Contabo

The web hosting portal Webhostlist continuously examines hosting providers and honors the best in each quarterly period. In the second quarter of 2016, Contabo was awarded first place in the categories "Best Service" and "Best Price-Performance Ratio"!

The selection procedure is based on high requirements. Based on strict criteria the website reviews each provider and also includes the opinion of genuine customers in its decision.

Receiving this award is a huge honor for us. At the same time the award serves as an extra motivation to be listed among the best in the future as well as to improve all processes and services in the future. First-class customer service is one of our key goals, after all.


As always, we remain available via e-mail and by phone directly via landline number – at any time, without any hotline fees, queues and complex menu selection – on 365 days per year.


No summer break at Contabo: Our new VPS plans are unbeatable!

Summer break? Not at Contabo! We have worked extremely hard and updated our entire VPS portfolio for you.
The result? Massive performance boosts combined with price reductions.

The VPS of our 100% SSD series especially benefit from this extensive overhaul. In the host systems of these VPS, we have built in only the latest and fastest Solid State Drives (SSDs) and completely abandoned traditional hard-disks. As a result, the I/O performance of your virtual server is enhanced multiple times. You get the maximum read-write rates – without compromise.
Each aspect of the 100% SSD series VPS has been improved. The new offers thus have more CPU cores, more RAM and more SSD space than before. On top of this, the monthly prices for these VPS have been reduced - really, what more could one ask for? Get your new 100% SSD VPS today!

An overview of the Contabo VPS series "100% SSD":

4 CPU Cores
12 GB RAM (guaranteed)
300 GB SSD disk space
100 Mbit/s switch port
Unlimited Traffic
1 Snapshot
No Setup fee
Rebate depending on the minimum contract period
Only 8.99 EUR / month!

6 CPU Cores
24 GB RAM (guaranteed)
600 GB SSD disk space
100 Mbit/s switch port
Unlimited Traffic
2 Snapshots
No Setup fee
Rebate depending on the minimum contract period
Only 14.99 EUR / month!

10 CPU Cores
50 GB RAM (guaranteed)
1200 GB SSD disk space
1 Gbit/s switch port
Unlimited Traffic
4 Snapshots
No Setup fee
Rebate depending on the minimum contract period
Only 26.99 EUR / month!

Those of you who know us already will not be surprised: We did not stop at this point! The HDD + SSD boost offers have been improved as well: The price of all HDD + SSD boost VPS have been reduced significantly. With a VPS from this series, you will receive an incredibly attractive offer!

An overview of the Contabo VPS series "HDD + SSD-Boost":

2 CPU Cores
6 GB RAM (guaranteed)
500 GB HDD
SSD boost
100 Mbit/s switch port
Unlimited Traffic
No Setup fee
Rebate depending on the minimum contract period
Only 6.99 EUR / month!

4 CPU Cores
14 GB RAM (guaranteed)
1000 GB HDD
SSD boost
100 Mbit/s switch port
Unlimited Traffic
No Setup fee
Rebate depending on the minimum contract period
only 11.99 EUR / month!

6 CPU Cores
30 GB RAM (guaranteed)
2000 GB HDD
SSD boost
1000 Mbit/s switch port
Unlimited Traffic
No Setup fee
Rebate depending on the minimum contract period
Only 19.99 EUR / month!

 Highspeed-support, high-end systems, lowest prices:

Posted by: Markus | Tagged as: , , , , , , 3 Comments

Price reduction for Contabo rootservers!

On time for the beginning of summer we reduce the prices once again with the intention to enable everyone a cheap and attractive entry (or upgrade) into the world of Dedicated Servers. Therefore we lower the monthly price of our three cheapest servers for another 10 Euro.

In detail, the following rootservers benefit from our latest price reduction:

Dedicated Server Quad:
Intel Core 2 Quad with 4x 2,4 GHz, 8 GB RAM, 800 GB HDD, 100 Mbit/s-Port
Price: 39,99€/month (instead of 49,99€)

Dedicated Server Core i7:
Intel Core i7 with 4x2,66 GHz, 12 GB RAM, 2x1000GB HDD, 100 Mbit/s-Port
Price: 49,99€/month (instead of 59,99€)

Dedicated Server 6-Core:
Intel Core i7 with 6x3,2 GHz, 24 GB RAM, 80 GB SSD and 2000 GB HDD, 100 Mbit/s-Port
Price: 59,99€/month (instead of 69,99€)

Every Dedicated Server can be ordered with a minimum contract length of just one month! In addition, we offer attractive discounts of up to one monthly fee, depending on your selected contract length.

Get started now!

Posted by: Markus | Tagged as: , , , , No Comments

(R)evolution: Dedicated Server 10-Core available now!

Evolution is simply natural selection.
The laws of nature ultimately decide, what will exist and what won't exist.

Contabo proudly presents you the latest outcome of the evolutionary process among servers.

Just released a couple of weeks ago, we have this new server in stock for you already: The Dedicated Server 10-Core! Featuring Intel's brand-new Xeon E5 2630v4 processor with 10 x 2.2 Ghz and powerful 256 GB REG ECC RAM - for a revolutionary 109.99 Euro/month!

You may add any combination of HDDs and SSDs, several RAID upgrades are available as well! The Internet uplink is a 1 Gbits switch port and we have no traffic limitations for your services!

State-of-the-art hardware and 10 cores are still not enough for you? No worries, you know us after all, at Contabo a lot is possible: Just double up and get 20 cores by adding a second CPU to your mainboard (for an additional 39.99 Euro/month)!

The minimum contract period is just one month and we do not charge any setup fees! In addition, we offer you up to 1 month free for a longer minimum contract period!

Go and check out our latest server here!


thumbnailPowered by Intel® Xeon Processors


How can I prevent my e-mails getting marked as spam?

You have your own e-mail server, but your e-mails are landing in the spam folder or do not even arrive? This can have several reasons. This tutorial will show you the most important tricks and often overseen configuration mistakes. If you have a webspace package, you will only need the point SPF of this tutorial. In this tutorial we will often use the fictional domain server.yourdomain.com and the IP address Please replace them with your own ones when you are doing the tests or configuration.

SMTP banner

The SMTP banner is the label of your e-mail server. When it connects to a different e-mail server, it is introducing itself with it. If you have a server from us, it will, at the beginning, answer with something like this:


A lot of e-mail providers will not accept such a label and send your e-mail directly into the spam folder. So it is better to choose a less generic one like:


Please note that it has to  be a fully qualified domain name (FQDN). That means there has to be a subdomain like "server" in front of yourdomain.com. You can request the current SMTP banner by connecting to your server with Telnet over port 25. You can do this in Windows by entering the following command into the Windows  command prompt:

telnet 25

Please use your own server IP here. If you are using Windows, you will have to activate Telnet first! (Start --> Control Panel --> Programs and Features --> Turn Windows features on or off--> wait a moment, then check the Telnet Client check box and finish with clicking on OK)
The output might look like this:

220 m1234.contabo.net ESMTP Postfix (Debian/GNU)

"m1234.contabo.net" is the important information in this line. You can leave the session by entering "quit" and hitting enter. In cPanel and Plesk, the mailserver's name in the SMTP banner is equal to the hostname. So you can alter it by changing the hostname in the administration panel.
If you are using Plesk on a Windows server, it is not so easy to change the banner. Please log into your server over RDP, open the tool "MailEnable" and go to: MailEnable Management --> Servers --> localhost --> Connectors. Then choose in the opening list SMTP, click on it with you right mouse key and open "Properties". In the opening window, there are four fields you have to fill in:

Local Domain Name

Here you have to enter you main domain. For example: yourdomain.com.

Default mail domain name

This is your e-mail server name in the SMTP banner. For example: server.yourdomain.com

DNS Addresses

Here you have to enter the DNS servers. If you have your server in one of our datacenters, the following addresses would work perfectly:

for Nuremberg:

for Munich:

Notification email address

Please enter an existing e-mail address.

If you are using Postfix instead of an administration panel, you can change the SMTP banner by using this command in the terminal:

postconf -e "myhostname = server.yourdomain.com" && postfix reload

Please replace "server.yourdomain.com" with the new domain name of the e-mail server.


The PTR, or also called reverse DNS record, is the counterpart of the A-record in a DNS zone.


server.yourdomain.com -->

PTR: --> server.yourdomain.com

Most e-mail servers only accept an e-mail, if the PTR is exactly the same as the name of the mailserver in the SMTP-Banner! If you have for example the following SMTP-Banner:

220 server.yourdomain.com  ESMTP Postfix (Debian/GNU)

You have to change your PTR like in the upper example, what can be done easily in the Customer Control Panel. Please notice, that you have to change the PTR of the IPv6 address too, if you are using IPv6 additionally to IPv4. It will not harm to do it anyway, if you are not sure.


With the SPF record you determine that it is only allowed to send e-mails from specific IP addresses. Many e-mail servers are considering e-mails from domains without SPF record as spam. You can add an SPF record in the Customer Control Panel with the DNS Zone Management. The following one should work in most cases:

86400 in TXT "v=spf1 +a +mx ~all"

It will allow the IP named in the A-record and the one of the mailserver, named in the MX-record.

If you use one of our webspace packages, please use the following one:

86400 in TXT "v=spf1 +a +mx +include:mail-relay.contabo.net ~all"

If you have a special configuration, you can use a tool like this to generate an individual SPF:



DKIM will help you to improve the reputation of your e-mails. Please take a look at our DKIM Tutorial for cPanel and Plesk!


We always do test our IP addresses, before we give them to our customers. But it is not impossible, that your IP is currently on a blacklist. This will cause your sending attempts to fail despite all your tries to achieve a perfect configuration. If you assume that your IP might be on such a list, you can test for the most important ones on this site:

MX-Toolbox Blacklist Check

Please enter the IP address of your server and wait some seconds for the test! If the IP is listed somewhere (marked in red), you should contact the owners of this list. They will offer a removal form on their home page. The IP should be removed in a few days. Some e-mail providers have their own lists, that can not be reviewed so easily. They normally will send you a bounce e-mail to signal, that the sending attempt failed, with the reason included in it. If they mention an internal blacklist, you can find below some links to the removal forms of such providers:


If you have problems getting your IP removed from such a list, please write an e-mail with the error message and the IP to support@contabo.com. We will help you solving this problem.

Additional points

If you have paid attention to all the points so far, and your e-mails have still problems with reaching the recipient or are landing in the spam folder, it is time to look for the reason in close detail. Have you got a reply when the e-mail was not accepted? Read this e-mail carefully. Often there stands the reason for this behaviour! If you have found such a message, but it does not help you, you are free to sent it with the complete header to our support. Our team of experts at support@contabo.com has a lot of experience with solving such problems!

If the e-mail is arriving but landing in spam, the header of the received e-mail might contain the reason for this classification. Furthermore many large e-mail providers like Google or Microsoft offer online information about their e-mail sending guidelines that are worth a look!

Please also take a look on the Website mail-tester.com. You can send an e-mail to the server here and the site will show you possible optimizations for your server and the e-mails!

If nothing helped

If you have worked through the whole tutorial, and there are still problems with sending e-mails, or you need help at some point, you can contact our support. We are there for you everyday from 8:00 to 23:00 (German time) at support@contabo.com.