New WEDOS Antispam


Dear WEDOS customers and fans, we would like to introduce you to the new WEDOS Antispam, which we deployed at the beginning of September. It has significantly reduced the number of spam inboxes and will ensure that spam is a rare exception in the future.

Dear WEDOS customers and fans, we would like to introduce you to the new WEDOS Antispam, which we deployed at the beginning of September. It has significantly reduced the number of spam inboxes and will ensure that spam is a rare exception in the future. Spammers have made a lot of progress in the last year and a half. The standard detection was no longer enough and you started to write to us asking if our current solution could be tightened up. However, this could already cause some regular commercial offers to be marked as spam. We have thus embarked on the development of two new solutions that represent the best of today.

Development of WEDOS Antispam

The first solution(WEDOS Antispam A1) was based on a proxy server that filtered incoming mail using more than 200 tools and methods before the email reached the mailserver. The results were very favorable, so we launched it for public beta test in August 2018. We really liked this solution because it could be easily deployed on VPS SSD, VPS ON and Dedicated servers. The only disadvantage was the need to have a trained person to calibrate the instruments on an ongoing basis.

The second solution(WEDOS Antispam B1) is based on the best that can be used today for detection, evaluates emails according to almost five hundred parameters, and uses “self-learning” algorithms to improve detection. Just to give you an idea, at 0:25 a very sophisticated spam pretending to be a newsletter arrived, which our WEDOS Antispam had not seen before, and so it was not evaluated as spam with a score of -0.44 (15 points are needed to be marked as spam). At 0:28 his modified version arrived to several other customers and he had already received a score of 0.47. By 10:56 a.m., it already had a rating of 17.62 out of 15 and was being labeled as regular spam, including future modified versions.

In the end, we decided for the second solution(WEDOS Antispam B1). The main reason was machine learning. Since we are probably the largest mail hosting provider in the Czech Republic, we have plenty of emails to learn from. Just to give you an idea – 2 to 5 million emails pass through our mailservers every day. The number varies by season and botnet activity. Of course, we also took into account the scalability and resilience of the entire solution.

So how does the new WEDOS Antispam work?

As soon as the email arrives the first tests are performed. This is where blacklists and hard rejections are used for the worst of the emails. You won’t get these emails and you don’t ever want to see them 🙂
The following is the scoring of the email in several categories. Various tools are used, including machine learning. At this point, three things can happen to the email. It is evaluated as spam, is suspicious or passes as clean.


If it is evaluated as spam, WEDOS Antispam will automatically insert the X-Spam-Flag: YES. This tag tells your email client to move the tagged email to the Junk folder in Thunderbird or Junk folder in MS Outlook (this folder must exist and the email client must have this enabled). If you use our web client RoundClube( or download mail via IMAP, our server will take care of everything automatically (but there must be a spam folder).
If your email client does not insert emails into the Spam folder, you need to enable it.

Find out more in our knowledge base

Suspicious emails

If an email gets a sufficient rating, but we are not sure that it is spam, the so-called greylisting is activated. This is a popular and very effective method to test your email. We will notify the mailserver that sent the email that we are unavailable and to try again later. For example, if the spammer forged the sender, the sender will not know anything about the email and will not resend it. However, if it was a regular email it usually arrives again in a few minutes.

Clean email and a glimpse into the future of the service

If the email is evaluated as clean, it will normally arrive in your mail. We are currently no longer working with him. However, we plan to expand WEDOS Antispam further in the coming months.

WEDOS Antispam B1.1

You too can get involved in machine learning. For now, you are sending us samples of problem spam manually. We have some automation ready, but it’s not quite what we want. In version B1.1 you will be able to mark an email as SPAM or HAM.

If some new spam appears that our WEDOS Antispam doesn’t already know, it will take a few hours for it to start marking it correctly. However, if more of our customers mark this spam as junk (SPAM), that will be a strong signal. The entire spam campaign can then be over in a matter of minutes.

On the other hand, we are most afraid of false positives. For regular emails where there is no group conversation, they are very unlikely (we have it set up that way). However, a solicited business offer could sometimes end up in spam. However, WEDOS customers will be able to mark such legitimate spam as HAM and thus improve its reputation for the next time.

WEDOS Antispam B1.2

However, with commercial offers, even the most polite ones, you can’t prevent someone from marking you as spam. People sometimes do this instead of unsubscribing because they know the mailserver for their mailbox will remember it and they won’t get another one. Therefore, with version B1.2 you can look forward to the introduction of the Bulk folder (provisional working name). All trade offers will be stored there. You’ll see them when you feel like it.

Of course, you’ll have full control over the filters and you can set which bulk mail to not put in your Bulk folder.

WEDOS Antispam B1.3

The new solution is very easy to bend and modify, which was one of the reasons we decided to go with it. So what WEDOS Antispam B1.3 will look like is up to you 🙂

Let us know what you’d like him to do and maybe we’ll add it to a future version 😉


This was one of the biggest changes for the mail service since August 2015, when we deployed a new mailserver. By the way, he hasn’t been overloaded once since then. Emails are an important part of shared web hosting, which we know very well, and we will continue to focus on them in the future. We have an experienced team of people.

NoLimit has long been the most popular shared web hosting in the Czech Republic. We provide free DDoS protection, IPS/IDS protection and now the new and improved WEDOS Antispam.
Thank you for your trust. Thanks to you, we grow every month and can continuously improve our services.