Ensure Spam Experts Server can Deliver to Destination Server
In some cases configuration changes are required to the destination server to ensure the Spam Experts servers can deliver to your destination server without interruption. Please ensure your destination server always accepts every message from our systems (only null sender callouts should be rejected if the recipient address does not exist). This includes disabling any SpamFiltering, and any SPF/Authentication type checks. As this check is already being performed by the Spam Experts systems.
Please ensure that the steps below are done, for correct delivery to Exchange servers.
- Whitelist delivery servers.
- Enable recipient verification, see Recipient verification in Exchange and Office 365.
- Disable any spam checks.
Please ensure that the steps below are done, for correct delivery to WHM/cPanel based environments.
- Make sure your Email Routing is set to Local Mail Exchanger and not at Auto Mail Exchanger (assuming email is handled locally).
- Ensure that the "catch-all" option is disabled for domains. This can be done by setting The following option:
- Whitelist delivery servers. This allows us to bypass sender/recipient/spam and relaying checks and ensure proper delivery. This can be done by adding the delivery IPs to the "Only-Verify-Recipient" option in:
- If you are using ConfigServer Firewall (CSF) within WHM/Cpanel, its advised whitelist delivery IPs there too. The delivery IPs can be added directly in the following location:
- Once added, restart CSF.
- Ensure that smtp_accept_max is set to cPanel default (100).
If cPanel detects non-local hostnames it will consider the domain remote and will stop accept email for it.
"Default Address" > "Discard the email while your server processes it by SMTP time with an error message
Exim Configuration Manager > Basic Editor > Access Lists
It's also possible to add the IPs directly in the following file:
Please make sure that the IPs are not present in /etc/skipsmtpcheckhosts , but only in /etc/trustedmailhosts as otherwise the status of the domain can appear to be catch-all.
Postfix & Amavis
If you are using Postfix with Amavis, there is an easy solution to allow our servers to bypass any filtering on your destination server.
In your Postfix configuration you need to add this line (or append it to your already existing smtpd_client_restrictions):
smtpd_client_restrictions = check_client_access hash:/etc/postfix/amavis_bypass
Then create a new file /etc/postfix/amavis_bypass with content:
# Bypass amavis entirely for emails originating from # Spam Experts' delivery cloud by immediately re-inserting # into Postfix # delivery.antispamcloud.com FILTER smtp:[127.0.0.1]:10025
Save the file and postmap it by entering:
Restart Postfix and all of the deliveries originating from our platform will bypass any virus-, spam- and spf checks initiated by Amavis.
This will not affect any of your other domains on this destination server, only connections originating from delivery.antispamcloud.com.
We have a multi-purpose script for Kerio which creates/updates an IP Address Group with our delivery IP's.
This list can be used to disable various limits/filters such as spamfiltering, SPF checking and the Spam Repellant.
To prevent your DirectAdmin system from rejecting deliveries you can add the delivery IPsor hostname to the following file:
For Hosted Cloud users Please simply add "delivery.antispamcloud.com" to the above mentioned file.
Disable spamfiltering on the destination server
We highly recommend you disable the spamfiltering on your destination server, as this would mean that both our platform as your server still scans it. This might lead to your destination server rejecting, blocking or removing messages that it considers to be spam, which passed our system.Having multiple layers of spamfiltering is generally a waste of system resources and a source of issues.
Disable SPF checking
When a message is delivered to a Spam Experts Filtering server it will check for SPF.
If the delivering server is allowed to deliver, we will accept it (given other parts of the Spamfiltering process also indicates its not spam)
When we are however delivering the scanned messages to your destination server, your server will most likely reject/block/delete it because it sees our servers as the delivering servers which is not listed in the SPF records as valid delivery system. To stop this behaviour from happening we highly recommend you to disable SPF checking. In most cases this needs to be done on server level and cannot be done on domain-level
Whitelist delivery servers
Its also generally a good idea to whitelist the delivery servers.
This allows us to bypass sender/recipient/spam and relaying checks and ensure proper delivery.
For hosted Cloud users, please always use where possible the delivery hostname: