# SecureMailMerge

> SecureMailMerge is an Outlook add-in for Microsoft 365 that sends personalized mail merge campaigns directly from your mailbox. It supports spreadsheets and Outlook contacts, processes campaign data locally on the user's computer, and works on Outlook for Windows, Mac, Web, and New Outlook.

SecureMailMerge is for organizations that want mail merge and bulk outreach without moving recipient data into a third-party email platform. Emails are sent from the user's Microsoft 365 account, so messages appear as normal Outlook email rather than from an external sending service.

Key capabilities include spreadsheet-driven personalization, Outlook contacts, individual attachments, dynamic CC/BCC, reply-to addresses, scheduling controls, many-to-one merges, custom headers including List-Unsubscribe, fallback values, and standard Outlook sending options such as read receipts and importance flags.

Important constraints:

- Requires a supported Microsoft 365 work or school mailbox. Personal Outlook.com, Hotmail, and Gmail accounts are not the target use case.
- Some organizations require Microsoft 365 admin approval before the add-in can be used.
- SecureMailMerge runs inside Outlook, so guidance should refer to Outlook and computer locale behavior rather than browser-only behavior.

## Canonical Pages

- [Homepage](https://www.securemailmerge.com/): Product overview and primary positioning.
- [Pricing](https://www.securemailmerge.com/pricing): Plans and licensing.
- [Help Center](https://www.securemailmerge.com/help): Central index of setup guides, troubleshooting, and feature docs.
- [Changelog](https://www.securemailmerge.com/changelog): Product updates and release history.
- [IT Security Guide](https://www.securemailmerge.com/help/it-security): Security posture and local-processing explanation.

## Core Help

- [Getting started](https://www.securemailmerge.com/help/getting-started): Install the add-in, prepare a spreadsheet, compose a message, and send a first campaign.
- [Create a mail merge template](https://www.securemailmerge.com/help/creating-a-mail-merge-template): Personalization tokens and email composition.
- [Mail merge with Outlook contacts](https://www.securemailmerge.com/help/sending-mail-merge-using-outlook-contacts): Create campaigns from personal or shared contacts.
- [Mail merge for New Outlook](https://www.securemailmerge.com/help/mail-merge-for-new-outlook): Compatibility guidance for New Outlook.
- [Permissions required for SecureMailMerge](https://www.securemailmerge.com/help/permissions-required-for-secure-mail-merge): Admin approval and permission scope.

## Feature Guides

- [Individual attachments](https://www.securemailmerge.com/help/sending-mail-merge-with-individual-attachments): Upload and match per-recipient files.
- [Many-to-one mail merge](https://www.securemailmerge.com/help/sending-mail-merge-with-many-to-one): Combine multiple spreadsheet rows into one email, including table output and combined attachments/CC/BCC.
- [Reply-to address](https://www.securemailmerge.com/help/setting-reply-to-address-in-mail-merge): Send from one address while routing replies elsewhere.
- [Schedule campaigns during specific hours](https://www.securemailmerge.com/help/sending-mail-merge-during-specific-hours): Limit sending to business-hour windows.
- [Schedule campaigns for a specific day](https://www.securemailmerge.com/help/sending-mail-merge-on-a-specific-day): Start campaigns on a future date.
- [Delay between messages](https://www.securemailmerge.com/help/sending-mail-merge-with-delay-between-messages): Pace message delivery.
- [Message preview in Drafts](https://www.securemailmerge.com/help/sending-mail-merge-with-message-preview): Generate a preview before sending.
- [CC and BCC recipients](https://www.securemailmerge.com/help/add-multiple-cc-or-bcc-recipients-to-a-mail-merge): Use static or spreadsheet-driven CC/BCC.
- [Custom headers and List-Unsubscribe](https://www.securemailmerge.com/help/adding-custom-email-headers-like-list-unsubscribe-to-mail-merge): Add mail flow headers and unsubscribe metadata.
- [Fallback default values](https://www.securemailmerge.com/help/specify-fallback-default-values-for-mail-merge): Handle empty spreadsheet fields safely.
- [Date formatting in mail merge](https://www.securemailmerge.com/help/date-formatting-in-mail-merge): Preserve Excel date formats and use `TEXT()` when exact output matters.

## Troubleshooting

- [Spreadsheet troubleshooting](https://www.securemailmerge.com/help/spreadsheet-troubleshooting): Common spreadsheet import and formatting issues.
- [Illegal characters in column headers](https://www.securemailmerge.com/help/illegal-characters-in-column-headers): Reserved sequences that break merge parsing.
- [Authentication window blank issue](https://www.securemailmerge.com/help/authentication-window-blank-issue): Sign-in fallback for a Microsoft Office login bug.
- [Shared mailbox support](https://www.securemailmerge.com/help/shared-mailbox-support): What is and is not supported with shared mailboxes.
- [Need admin approval](https://www.securemailmerge.com/help/need-admin-approval): What to do when Microsoft 365 blocks installation or consent.

## Optional

- [Articles and knowledge base](https://www.securemailmerge.com/articles): Broader educational content about Outlook, mail merge, and email workflows.