Qurb is a desktop-based software spam filter that claims to weed out junk mail without any configuration.
The software creates a 'white list' of authorised senders by analysing existing email messages on the user's computer.
It then looks at the content of messages from unknown senders and points the user to email that might have been mistakenly flagged as spam.
CA's acquisition is intended to strengthen its position in the market for consumers and small and mid-sized businesses.
The transaction follows the acquisition of firewall developer Tiny Software.
Qurb's software is used on nearly one million computers worldwide. A consumer version is available for download here.
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