ForthWrite vs Kerna

ForthWrite drafts email replies using a writing profile learned from a user's sent email. The free plan works with Gmail and Outlook on the web, while an Outlook add-in is available for Outlook desktop on Windows or Mac. Free accounts get 10 drafts per week; the plan excludes custom persona, auto-draft, batch drafting, coaching, analytics, and dictation. Pro includes unlimited drafts, auto-draft, batch drafting, custom persona, RAG, and dictation. It is listed at $24 a month billed annually, and the page also shows $29/mo. Teams has a two-seat minimum and includes Pro features, a shared team persona, Prompt Lab, review records, and team analytics. Slack drafting requires Standard or Pro. A Claude connector can produce a draft or contact summary, but does not send mail or open a mailbox. ForthWrite says it passed Google's CASA Tier 2 assessment for its restricted Gmail read-only scope. Its privacy policy says routine thread content is not kept after a draft is returned, while sent-email snippets are stored to learn the user's voice. Attachments are not currently read or analyzed.

Kerna is an AI email assistant for Gmail and Outlook on macOS, Windows, and the web. At a user’s request, it sorts open messages into categories such as Urgent, Respond, Invoice, Waiting, and Notification; users can also set custom categories and industry taxonomies. It drafts replies based on the full thread, with controls for intent and tone, and makes structured thread summaries for conversations of up to 50 messages. It can summarize attachments, extract selected fields into exportable tables, and translate inbound messages and outbound replies in 45 languages. Integrations include Calendar, Contacts, and Sheets as well as Gmail and Outlook. Kerna says it acts only when a user initiates a request, processes content in memory, discards it afterward, and redacts personal data before it reaches the inference provider. Its trust information reports TLS 1.2 or higher in transit and AES-256 encryption at rest. Kerna has a free plan; paid plans start at €12/mo. Outlook requires a Microsoft-hosted mailbox; POP or IMAP and on-premises Exchange are unsupported.