Inbound spam filtering


This documentation pertains to the spam filtering service. It is not intended for customers of hosted emails plans from Mailcheap (which include spam filtering). This service is meant to be used with your existing email infrastructure.

Get started with Mailcheap’s AI anti-spam and anti-virus filtering / mail forwarding service in 3 steps:

  1. Adding relay domain(s) in admin panel: this step will tell Mailcheap’s filter server to forward/relay emails to your destination (target) mailserver.
  2. Updating MX record for your domain: this step will let all mailservers on the internet know where to route your emails.
  3. Whitelist Mailcheap’s filter server and/or disable email delivery from all other mailservers on your destination (target) host: this step would make sure only filtered emails are delivered to your users’ mailboxes as well as avoid filtering already filtered emails.

Next, we will look at each of the above steps in detail.

Add relay domains


Relay domains are added in the admin panel located at your Mailserver hostname or Filter server hostname. The server hostname and login credentials can be found in the provisioning ticket/email titled “New Product Information” or “Your Filter plan has been provisioned”. View email history from the client area by clicking here.

Step 1. Select tab Domains > Add

Add domains

Step 2. In the New domain / General window enter the following details:

  • Name: your domain name.
  • Type: choose Relay domain.

Once the required fields are filled, click ‘Next’

New domain / General window

Step 3. In the New domain / Relay domain window enter the following details:

  • Target host: mailserver hostname to which mails will be forwarded.
  • Service: choose smtp

Once the required fields are filled, click ‘Next’

New domain / Relay domain window

Step 4. In the New domain / Options window click Submit New domain / Options window


New domain / Options window will appear different to Filter/Backup plan users since you do not have permission to create domain administrators. Press Submit to create your relay domain.

New domain / Options window for Filter/Backup plan users

Step 5. That’s it! Your Relay domain is now added and should show in the list.

Updating MX record

What is an MX record?

An MX record tells senders how to send email for your domain. When your domain is registered, it’s assigned several DNS records, which enable it to be located on the Internet. These include MX records, which direct the domain’s mail flow. Simply put, an MX record identifies the mail server that is responsible for handling e-mails for that domain name. Properly configured & propagated MX record is necessary to receive emails.

How do I setup/update an MX record?

Setting up an MX record at your domain registrar/nameserver (for your domain name) is a very simple process that can be done in under a minute!

General Instructions

  • Hostname → @
  • Mailserver Hostname → (Use your own value!).
  • Record type → MX
  • Priority / Preference → 0 (0 is the highest priority)
  • TTL → 1800
Hostname Mailserver hostname Priority
@ (Use your own value!) 0


Make sure to remove your old host’s MX records (if any).

Specific Instructions

Destination host customization


This step is not mandatory but it is highly recommended.

Whitelist Mailcheap’s filter server.

Whitelist Mailcheap’s filter server in your destination (target) host so that mails are not filtered twice and there are no false positives due to filtering already filtered emails.

Disable email delivery from all other mailservers

By disabling email delivery from all mailservers except Mailcheap’s filter server, you can be sure that your users’ mailboxes gets only filtered emails.


There are many approaches to implement the above recommendations by modifying your anti-spam service, SMTP server and/or firewall configuration. Please consult your destination email provider for implementation.


Whitelist & blacklist senders

Whitelist & blacklist rules can be set in console. Once logged in, select from the menu bar > Tools > Whitelist & blacklist.

Increase or decrease spam sensitivity

In admin panel go to Domains tab > Press edit button for relay domain > Content filter > increase both threshold value fields. Default spam threshold is 4.0. This is the spam score at which emails are quarantined. Experiment by increasing both threshold value fields (spam mails are never thrown away, its always quarantined) to higher values for each relay domain.