SpamSieve review
A focused local Bayesian filter for Mac users who want detailed mail controls.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
SpamSieve is a macOS application for filtering unsolicited email within supported Mac email clients. It uses Bayesian analysis and training from good and spam messages to classify mail, then moves suspected spam to a separate mailbox instead of deleting it. The product is aimed at Mac users who want local filtering across multiple accounts, with more control than a basic mailbox-level spam folder provides. It is especially suited to people who want to manage allowlists, blocklists, scoring, and custom matching rules from within their desktop mail workflow.
The published plan is straightforward: SpamSieve costs $39.99 as a one-time purchase and covers one person or one computer. A 30-day free trial is available. The integration list includes Apple Mail, Airmail, GyazMail, MailMate, MailMaven, Entourage, MailForge, Mailsmith, Postbox, PowerMail, and Microsoft Outlook in legacy mode. AppleScript is also supported. This breadth makes the application useful for Mac environments built around established desktop clients, while its mailbox-app deployment keeps filtering close to the user's mail workflow rather than placing it at the server gateway.
Its main strength is control over classification: users can train the filter, define header or body-text rules, apply attachment-name rules, review spam scores and color indicators, inspect statistics and logs, and use special mailboxes for remote training. The trade-off is a narrow platform and client scope. SpamSieve is not a server-side gateway, supports macOS rather than other platforms, and cannot directly integrate with New Outlook. Malware scanning is also explicitly false, so organizations seeking centralized filtering, broader platform coverage, or malware protection should choose a different category of product. Mac users who want local Bayesian filtering and detailed rules are the clearest fit.
SpamSieve pros and cons
- Where it wins
- Bayesian filtering improves through training from good and spam messages.
- Custom rules, scoring, logs, statistics, and attachment-name analysis.
- Supports multiple accounts across a wide range of Mac mail clients.
- Where it doesn't
- Runs only on macOS and supported Mac email clients.
- New Outlook cannot be directly integrated; legacy Outlook is supported.
- Malware scanning is not included.
SpamSieve fact sheet, pricing and score →
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
Last updated · How we research and update