For Microsoft 365 administrators
SecureMailMerge is an Outlook add-in. It processes campaign data on the user's device and sends through the user's own Microsoft 365 mailbox. This page covers permissions, data flow, deployment and licensing so you can approve, pilot or decline with the facts.
Free plan available. Requires a Microsoft 365 work or school account.
Publisher: Sol Inventum OÜ, Tallinn, Estonia. Listed on Microsoft AppSource since 2023.
Publisher Attestation published with Microsoft (self-reported)
4.9/5 from 74 ratings on AppSource Made for your Outlook. New OutlookClassic OutlookMacWeb No Word required.No Exchange changes to deploy.
Two steps inside your tenant, one license check with us.
01 / ON THE DEVICE
The user picks a spreadsheet and writes the message in Outlook. The add-in reads the file locally and generates one message per row inside the Outlook client. No campaign data is processed on a server.
02 / THROUGH THE TENANT
Messages are sent through the user's own Microsoft 365 mailbox via Microsoft Graph, like any email the user writes. They are saved in Sent Items, and your retention, DLP and audit controls keep applying.
03 / WHAT WE SEE
Our licensing server receives the mailbox's primary email address, the product name and a timestamp to check for a license. Anonymous usage counts and error reports are sent separately and contain no recipient data. Recipient data, message content and attachments are never sent to us.
Spreadsheet and attachments
Picked by the user from their own files and read locally by the add-in.
Processed in Outlook on the device
One message per row, generated inside the Outlook client.
Sent through Microsoft 365
Via Microsoft Graph from the user's own mailbox, under the user's identity. Saved in Sent Items.
License check with www.securemailmerge.com
The mailbox's primary email address, the product name and a timestamp. No campaign data. Free users' addresses are not stored after the check.
Anonymous usage counts and error reports contain no recipient data. Both can be blocked at the firewall and the add-in keeps working.
Evaluation checklist
Permissions, data handling, deployment and the limits that stay in your hands. Each item links to the page that documents it.
All delegated, granted per user. Find the enterprise application in Microsoft Entra by its application ID.
Application ID: e9ce170b-5d81-44cf-8924-08f30720db3c
| Permission | Type | What it is used for |
|---|---|---|
| User.Read | Delegated | Signs the user in and reads their profile and email address, to show the sending account in the add-in and run the license check. |
| Contacts.Read | Delegated | Reads the user's own contacts to build a recipient list. |
| Contacts.Read.Shared | Delegated | Reads contacts in shared mailboxes the user already has access to. |
| Calendars.Read.Shared | Delegated | Reads only the Outlook category list of those shared mailboxes, so shared contacts can be filtered by category. No calendar or event data is read; Microsoft's permission model offers no narrower scope, confirmed with Microsoft support. |
| Mail.ReadWrite | Delegated | Creates draft messages in the user's own mailbox while attachments upload and holds each generated message until it is sent. |
| Mail.Send | Delegated | Sends the generated messages from the user's own mailbox. |
| MailboxSettings.Read | Delegated | Reads mailbox settings so the add-in respects your sending limits, and the user's own Outlook categories. |
| offline_access | Delegated | Refreshes the access token during a campaign so the user is not asked to sign in every few minutes. The refresh token stays in Outlook, and the user signs in again after closing the add-in or Outlook. |
| openid, profile | Delegated | Standard OpenID Connect sign-in. |
Security review
Campaign data is processed in Outlook on the user's device, and it leaves only as mail sent from the user's own mailbox.
SecureMailMerge was designed for minimal trust. All primary functionality runs on the user's computer, with no processing on a server. The add-in's Microsoft Graph token is only ever transmitted between the user's computer and Microsoft.
The only server of ours the add-in depends on is the licensing server, which never receives campaign data. We have no SOC 2 report or ISO 27001 certification of our own; the certifications of our hosting providers are listed in the security overview.
Removing the add-in in "Integrated apps" takes it out of users' Outlook after Microsoft's propagation delay. Consent already granted stays on the SecureMailMerge enterprise application in Microsoft Entra until you revoke it there, under "Enterprise applications" > "Permissions".
Share the Trust Center with ITMicrosoft 365 (Microsoft Graph)
Sending mail, reading contacts and mailbox settings. Required, already allowed in your tenant.
www.securemailmerge.com
Loading the add-in (GET) and the license check (POST to /api/license). Required.
analytics.solinventum.com
Anonymous usage counts on our self-hosted Rybbit. Optional, can be blocked.
Sentry (o4504911921414144.ingest.sentry.io)
Error reports with technical information only. Optional, can be blocked.
The license portal at licensing.solinventum.com is not contacted by the add-in. Only the people who manage licenses need it, in a browser.
Sol Inventum OÜ, an EU company registered in Estonia. Sepapaja 6, Tallinn. Company number 14665482.
About us4.9/5 from 74 ratings on Microsoft AppSource, where SecureMailMerge has been listed since 2023.
Read the reviewsA self-reported questionnaire published by Microsoft, not a Microsoft security review. Security contact [email protected], also published in security.txt.
View the attestationFree to evaluate. One license per person who sends, using their own email address to remove the footer.
Every feature works in the free version, with no time limit. It adds a short promotional footer to each email, so a pilot needs no purchase.
Compare the plansOnly users who send campaigns need one; recipients need nothing. Licenses are reassignable within your subscription when staff change. No limit on campaigns, emails or attachments, so there are no per-recipient or per-message charges.
Full pricing detailsPay by card or PayPal on our website, or buy the SecureMailMerge SaaS offer on Microsoft AppSource for Microsoft 365 billing. Microsoft purchases are billed, resized and cancelled in the Microsoft 365 admin center, with volume discounts from 10 licenses.
Set up a company subscriptionWebsite and Microsoft purchases are both assigned to email addresses at licensing.solinventum.com. The subscription owner can invite delegated admins who assign licenses without billing access.
Assign licenses to your teamDeploy to a small group, let them send on the free version and check the controls you care about. Nothing to buy until you widen the rollout.
01
In "Settings" > "Integrated apps", choose "Specific users/groups" instead of the entire organization. Users need a Microsoft 365 Business or Education mailbox; the add-in appears in their Outlook without any action from them.
See the deployment steps02
If your tenant lets users consent, they accept the permissions at first sign-in. If they see "Need Admin Approval", grant consent for everyone with the admin consent link.
Grant admin consent03
The free version has every feature and adds a promotional footer. Check that the messages sit in the user's Sent Items and that the footer is the only difference from a normal email.
What users do first04
Block the analytics host and Sentry if you want to, ask users to set a custom header (names start with x-) so your mail flow rules can see the traffic, and grant Send As where a shared mailbox is the sender.
Firewall requirementsShort answers, each with the page that documents it.
Visit the Help CenterDelegated only, no application permissions. The add-in signs the user in and calls Microsoft Graph as that user with User.Read, Contacts.Read, Contacts.Read.Shared, Calendars.Read.Shared, Mail.Send, Mail.ReadWrite and MailboxSettings.Read, plus the standard openid, profile and offline_access sign-in scopes. Separately, its add-in manifest declares the ReadWriteMailbox permission level of the Outlook add-in API.
Read the permissions guideNo campaign data is sent to us. Spreadsheets, message content and attachments are processed in Outlook on the user's device and sent through the user's own mailbox via Microsoft Graph. Our licensing server receives the mailbox's primary email address, the product name and a timestamp. Anonymous usage counts and error reports contain no recipient data and can be blocked at the firewall.
Read the security overviewYes. In "Integrated apps", choose specific users or groups instead of the entire organization, and widen the assignment later. Deployed users can use every feature for free with a promotional footer, so a pilot needs no licenses.
See the deployment stepsWho has the add-in is set in "Integrated apps". Whose emails go out without the footer is set by license assignment on the licensing server, where the subscription owner can invite delegated admins to assign licenses without billing access.
See centralized license managementYes. SecureMailMerge supports New Outlook, classic Outlook on Windows, Outlook for Mac and Outlook on the web with a Microsoft 365 work or school account. Outlook.com and personal Microsoft accounts are not supported.
Read about New Outlook supportRemove it in "Integrated apps"; it disappears from users' Outlook after Microsoft's propagation delay. Revoke the granted consent under the enterprise application in Microsoft Entra if you want it gone there too. Removing the add-in does not cancel a subscription. Cancel website purchases on the licensing server and Microsoft purchases in the Microsoft 365 admin center; licenses stay active until the end of the paid term.
See removal and cancellationSend security questions, vulnerability reports and requests for a signed DPA to [email protected].