ClrStream

ClrStream is an email security, continuity and durability solution for MS Exchange, Office 365, MDaemon, Postfix, PostMaster, Zimbra & other mail solutions. ClrStream protects email servers from Spam, Virus, Ransomware and DDOS attacks. It also provides email continuity when the primary mail server is unavailable or down.

According to the vendor, when bundled with Vaultastic, email data durability is guaranteed at 99.99999999999%. All without any lengthy and costly email service migrations.