Mailbutler Smart Assistant vs Newton Mail

Mailbutler Smart Assistant adds AI writing and email-management tools to Apple Mail, Microsoft Outlook, and Gmail. It drafts messages from keywords or prepares replies using details a user supplies, with controls for format, length, style, tone, and language. It can summarize selected emails, identify to-dos for Mailbutler Tasks, and suggest spelling and grammar improvements to drafts. Mailbutler says the assistant uses OpenAI GPT-4o. Smart Assistant is included in a 14-day trial, then requires a Smart or Business subscription. The separate free Starter plan includes a visible Mailbutler watermark on sent emails. Mailbutler says email subjects and bodies are processed by Microsoft Azure OpenAI Service in the EU, with personal data redacted before submission to the underlying model. It also says backend data is encrypted and that it is ISO/IEC 27001 certified and GDPR compliant. Apple Mail support is listed for macOS Tahoe, Sequoia, Sonoma, and Ventura; mobile apps require iOS 15 or later or Android 7 or later.

Newton Mail is an email app for Mac, Windows, iPhone, and Android, with a unified inbox, offline access, scheduled sending, and calendar tools. It supports Gmail, Google Workspace, Outlook, Microsoft 365, and IMAP providers, and connects with apps including Todoist, Evernote, OneNote, Trello, Asana, Claude, and other AI apps. The free plan has no time limit and supports up to two Gmail, Outlook, or IMAP accounts, 15 read receipts per month, and 20 AI actions per day. Pro costs $5 a month with annual billing and includes unlimited email accounts, read receipts, and templates, plus 200 AI actions daily. Team costs $12 a month with annual billing and a two-seat minimum; workspaces include three shared inboxes. Teams can share threads, comment, reply on behalf of others, and view activity. Newton says credentials are encrypted with AES-256-GCM and that it does not see email passwords through OAuth sign-in. Attachments are limited to 25 MB. A 14-day free trial is available.