MailMerge365

OutMass is a browser extension for Chrome and Edge that adds mass-email and mail-merge capability to Outlook on the web. Campaigns are built inside Outlook itself, and every message is sent through the user's own Microsoft account via the official Graph API, so recipients see a normal email rather than a bulk sender. Microsoft 365 and personal Outlook accounts are both supported. Campaigns start from a CSV: each column becomes a merge tag, and every recipient gets a personalized message. Open and click tracking show who engaged, and a daily reply check catches responses. Automated follow-ups re-contact non-openers and stop the moment someone replies. Scheduled sending, per-day send limits, A/B subject testing, an AI email writer, reusable templates, campaign reports with CSV export, unsubscribe links and OneDrive-link attachments complete the toolset. The interface is available in 13 languages. Free plan: 250 emails per month. Starter: $9/month for 2,500. Pro: $19/month for 10,000.

The privacy focused mail merge add-in for Outlook and Microsoft 365. Send marketing campaigns or confidential internal newsletters with the same tool. Your data never gets uploaded to any servers like with other tools, therefore stays safe with you at all time. The emails are sent from your own email address as if you sent them personally, so you get terrific response rates from people. Use Outlook to write your formatted template email, add some personalization tokens from a spreadsheet or your address book, add any number of attachments and images and then watch as SecureMailMerge generates your emails for you right in front of your eyes. Works on Windows, Mac and Browser versions of Outlook 365 and requires a Microsoft 365 Business subscription. Has support for Shared Mailboxes.