Creating an SPF
You may be receiving spam where the sender information is specified as your domain. In this case, the recommended solution would be to add an SPFSender Policy Framework is an open source equivalent to Caller ID. record for your email domain.
This ensures that spammers may not spoof your email domain when sending email to your Kerio Connect.
It also prevents spoofing of your domain for messages sent to other email servers that perform lookups against SPF. This requires a special DNSDomain Name System - Enables the translation of hostnames to IP addresses and provides other domain related information. configuration called a TXT record.
Many DNS hosting providers may not support configuration of such records. If you do not host your own DNS, you need to contact your DNS hosting provider (usually the domain registrar) to find out if they support configuration of TXT type DNS records.
Given an outgoing IP of 63.194.168.220, our SPF records would be created exactly this way:
SPF
"v=spf1 mx ip4:63.194.168.220 -all"
For further details on creating SPF records, see Creating an SPF DNS Record.