What is SpamExperts and how does the spam filter work?

SpamExperts is a professional email filtering solution that filters unwanted and potentially dangerous messages before they reach the actual email mailbox.

Inbound filtering routes the email traffic of a protected domain through the SpamExperts infrastructure first. There, the messages are analyzed and then—if accepted—forwarded to the actual mail server.

SpamExperts also offers features for controlling and analyzing email traffic, such as spam quarantine, log search, allow and block lists, filter settings, and reports.

Briefly explained: For incoming filtering, SpamExperts sits between the sending mail server and your actual email server. This allows suspicious messages to be detected before they reach your mailbox.

How does SpamExperts work? #

Without prior filtering, an incoming email is generally sent directly to the mail server responsible for your domain.

With SpamExperts Incoming Filtering, the simplified path looks like this:

Sender
   ↓
SpamExperts
   ↓
Analysis and filtering
   ↓
Destination mail server
   ↓
Email mailbox

For this method to work, the domain's MX records are configured so that incoming messages are first delivered to SpamExperts.

SpamExperts, in turn, knows the actual destination mail server and forwards accepted messages there.

We will explain the technical setup separately at Set up SpamExperts incoming filtering and configure MX records.

What does SpamExperts check for incoming emails? #

A modern spam check is not based on just a single feature. When evaluating a message, various technical information and filtering mechanisms are taken into account.

These include, among other things, sender information, message properties, and various authentication and reputation characteristics.

SpamExperts supports incoming filtering checks, including:

• SPF
• DKIM
• DMARC
• Sender information
• news characteristics
• Spam classification

How strictly certain messages are handled also depends on the filter settings of the respective domain.

Important: A spam filter should not be „optimized“ by randomly disabling security checks. Exceptions should only be set up if the cause of a misclassification is understood.

What happens to detected spam? #

How a message classified as spam is handled depends on the configuration.

When spam quarantine is enabled, corresponding messages can be held back in SpamExperts. This allows you to check suspicious messages without having to deliver them directly to the actual mailbox.

We explain how to find and edit messages there under Using Spam Quarantine in SpamExperts.

What is spam quarantine? #

Quarantine is a separate area for messages that have been handled accordingly based on the filter score.

There you can check, for example:

• which sender sent a message
• who it was addressed to
• when the message was processed
• as classified by SpamExperts

Depending on permissions and configuration, messages can be investigated further there and corresponding actions can be taken.

What happens with a mistakenly blocked email? #

No spam filter can perfectly classify every single message under all circumstances.

It can therefore happen that a legitimate message is incorrectly classified as spam. This is often referred to as False Positive referred to as.

In this case, it should first be checked why the message was classified accordingly.

Quarantine and especially the log search help to trace the processing of a message.

We explain how to examine the chat history at SpamExperts Log Search: Trace E-Mail History.

What happens if spam is still delivered? #

The reverse case is also possible: an unwanted message is not recognized as spam and reaches the inbox.

Such a message should not be handled simply by indiscriminately blocking entire domains.

SpamExperts offers a training feature that allows corresponding messages to be reported as spam.

We explain the procedure under Train SpamExperts Filter: Report spam and ham correctly.

What does Ham mean? #

In the context of spam filters, a legitimate, desired message is often Ham referred to as.

Simplified:

Spam
→ unwanted message

Ham
→ legitimate message

Training should be used selectively. Not every unwanted, but technically legitimate message is automatically spam.

What is the sender allow list? #

With the Sender Allow List certain senders can be specifically allowed.

Such an exception can be useful if legitimate messages from a known sender are repeatedly mishandled and the cause has been duly investigated.

However, allow lists should not become unnecessarily large. Every exception alters the normal filtering decision.

We explain the setup at Sender Allow List: Allow senders in SpamExperts.

What is the sender block list? #

The Sender Block List serves to specifically block certain senders.

Depending on the rule used, SpamExperts can distinguish between different sender information in an email.

A block list should therefore be used selectively and not serve as a replacement for actual spam detection.

We explain how to correctly block senders at Sender Block List: Block senders in SpamExperts.

Attention: Your own domain should not simply be placed on the Sender Block List to prevent spoofing. SPF, DKIM, and DMARC are specifically intended for protection against forged senders.

What is Log Search? #

The Log Search is among the most important tools for email delivery issues.

This allows you to track how SpamExperts has processed a message.

This is helpful, for example, when:

• an expected email did not arrive
• a message was blocked
• a message ended up in quarantine
• you want to check the status of a specific email
• you want to investigate a delivery error

For a specific missing message, log search is usually much more helpful than general changes to the filter settings.

What are the filter settings? #

The filter settings determine how SpamExperts handles certain incoming messages.

These include settings for quarantine as well as various inspection mechanisms for incoming messages.

The default values should not be changed drastically without a specific reason.

We explain how to evaluate the settings and adjust them sensibly at Configure SpamExperts filter settings correctly.

What are protection reports? #

SpamExperts can provide reports that give you information about filtered messages without you having to constantly open the control panel.

This is especially helpful for users who want to check regularly whether relevant messages have been filtered.

We cover setup and use under Set up and manage SpamExperts protection reports.

What is incoming filtering? #

Incoming Filtering refers to the filtering of incoming messages.

The basic message path is:

Internet
   ↓
SpamExperts Incoming Filtering
   ↓
Destination Mail Server
   ↓
Recipient

For SpamExperts to receive incoming messages, specifically the MX records and the destination for subsequent delivery must be set up correctly.

What is outgoing filtering? #

Outgoing Filtering concerns outbound email traffic, on the other hand.

Simplified:

Sender / Application
        ↓
SpamExperts Outgoing Filtering
        ↓
Receiving Mail Server

Incoming and outgoing filtering are technically different functions and can be used independently of each other.

We explain how to set up outgoing shipping at Set up SpamExperts Outgoing Filtering.

Why is outgoing email traffic filtered? #

Spam is not exclusively generated by external senders. Compromised email accounts, stolen access credentials, or abused applications can also send unwanted messages.

Outgoing filtering can help detect suspicious outbound email traffic and protect the reputation of the email infrastructure used.

If a compromised sender is detected, the root cause must also be eliminated. A filter does not replace the securing of the affected account, device, or website.

What role do MX records play? #

MX stands for Mail Exchange. MX records in the DNS determine which mail servers are responsible for incoming messages of a domain.

With SpamExperts Incoming Filtering, the relevant MX records point to the filtering infrastructure. SpamExperts processes the incoming messages and then forwards accepted emails to the configured destination mail server.

Important: Do not change MX records on speculation. An incorrect MX configuration can disrupt the delivery of incoming emails.

What role do SPF, DKIM, and DMARC play? #

SPF, DKIM, and DMARC are email authentication methods that play an important role in protecting domains and evaluating email traffic.

Procedure	Simplified explanation
SPF	defines which systems are allowed to send emails for a domain
DKIM	uses cryptographic signatures to verify specific message components
DMARC	builds on SPF and DKIM and adds, among other things, alignment and policies

These procedures are not the same as a spam filter. They supplement spam and spoofing defense with technical authentication mechanisms.

We handle the SPF configuration for SpamExperts separately at Properly setting up and checking SPF for SpamExperts.

Can SpamExperts block every spam email? #

No. No reputable spam filter can guarantee that every unwanted message will be detected while every legitimate message is always correctly delivered.

Spam techniques are constantly changing and some messages exist in a borderline area between desired and undesired communication.

Therefore, in addition to automatic filtering, SpamExperts provides additional tools, such as:

• Quarantine
• Log Search
• Filter training
• Allow Lists
• Block Lists
• Filter settings
• Reports

Why shouldn't I just allow every sender? #

An allow list is an exception to the normal filtering decision.

If a new allow-list entry is created immediately for every misidentified message, a large collection of exceptions will grow over time.

The better approach is:

Check message
      ↓
Check Log Search
      ↓
Understand the cause
      ↓
Choose appropriate measure
      ↓
If necessary, training or allow list

This ensures the filter configuration remains traceable.

Why shouldn't I block every spam sender? #

Many spam campaigns use constantly changing or fake sender addresses.

Manually blocking each individual address is therefore often not the most effective strategy.

If similar spam messages get through repeatedly, filter training is recommended first. A block list is more suitable for targeted and traceable blocking of specific senders.

How do I access SpamExperts? #

At CURIAWEB, access to the SpamExperts administration is provided via the customer center or the corresponding service.

We explain the exact procedure under Login to the SpamExperts Dashboard via the CURIAWEB Customer Center.

The SpamExperts Dashboard #

After logging in, the SpamExperts management interface is available to you.

Depending on the booked service and your permissions, you will find functions there for inbound or outbound filtering, logs, quarantine, protection rules, and reports.

You can find an orientation through the most important areas under SpamExperts Dashboard Explained: Overview of All Key Features.

SpamExperts does not replace a secure email configuration #

SpamExperts is an additional protection and control layer for email traffic. However, the service does not replace basic security measures.

This also includes:

• strong and unique passwords
• Protection of the end devices used
• current software
• correct DNS configuration
• SPF, DKIM, and DMARC
• careful handling of attachments and links

Even a message that has bypassed a spam filter should not automatically be considered trustworthy.

What to do if an email is missing? #

If an expected message has not arrived in your inbox, you should not change your filter settings immediately.

Proceed systematically:

1. Note sender and recipient.
2. Note the approximate shipping time.
3. Check the spam quarantine.
4. Search for the message about log search.
5. Check the classification or delivery status displayed there.
6. Only decide on further measures after that.

This procedure prevents global filter rules from being changed unnecessarily due to a single missing message.

What to do when spam ends up in your inbox? #

If a spam message has been delivered, you should initially not reply to it and not open any contained links or attachments.

To improve filter classification, the message can subsequently be specifically trained as spam.

You can find the exact procedure at Train SpamExperts Filter: Report spam and ham correctly.

Summary #

SpamExperts protects email traffic through an upstream filtering and analysis layer. With incoming filtering, messages are first processed by SpamExperts and then forwarded to the actual destination mail server.

For daily management, quarantine, log search, filter training, sender allow list, sender block list, filter settings, and protection reports are available, among other things.

Outgoing Filtering extends the concept to outgoing messages and is technically separate from incoming filtering.

When encountering problems, you should not immediately change allow lists, block lists, or filter values. First, use quarantine and log search to understand how the message in question was processed.

This makes SpamExperts not only a spam filter, but also an important tool for the analysis and control of email traffic.