Paubox Email Encryption vs Rspamd

Paubox Email Encryption is a web service for sending protected email, presented through its healthcare solution. Delivery uses a link, and recipients verify access with a password. Outlook and Gmail integrations are included, along with administrator access controls. Messages do not expire, and attachments have a listed limit of 150. Paubox has no free plan, but offers a 14-day trial. Its three plans are billed annually and cover up to five senders: Standard costs $29 a month, Plus costs $59 a month, and Premium costs $69 a month. The pricing note gives a starting price of $29/mo on an annual term. Buyers can compare the plan levels while considering link-based delivery, password verification, supported mail integrations, and the administrative controls available for a small sender group.

Rspamd is an email security engine for filtering phishing, business email compromise, malicious attachments, and spam. It scores messages using reputation, sender authentication, content analysis, and machine learning. Authentication checks cover SPF, DKIM, DMARC, and ARC; malware scanning can use ClamAV or commercial antivirus engines. Administrators can define custom rules through the Lua API and configurable maps and selectors. Rspamd works with mail transfer agents including Postfix, Exim, and Sendmail, and its ClickHouse and Elasticsearch integrations provide visibility into attack patterns and detection rates. It is designed for gateway deployment and can run on-premises, keeping message data in the operator's environment without a mandatory vendor cloud. The detection engine is open source under Apache 2.0 and is available for Linux, macOS, and self-hosted use. Rspamd says its event-driven C core scans hundreds of messages per second per core and can scale from a single server to billions of messages a day. The open-source engine is listed at free. Scale costs £100 a month, with 5K mailboxes; hosted and enterprise plans have custom pricing. Premium plans offer support from core engineers, with enterprise SLA options.