Features and feature comparison

Our solution at a glance and in benchmark

Features: What our solution is able to do Feature comparison with competitors Quickstart: Signatures in minutes

🔗Overview

Set-OutlookSignatures is the most advanced, secure and versatile free and open-source tool for managing email signatures. The optional Benefactor Circle add-on unlocks even more powerful features tailored for business environments.

It delivers everything you'd expect from a modern solution: Centralized management, seamless deployment, and full control across all Outlook editions on all platforms: Classic and New, Android, iOS, Linux, macOS, Web, Windows.

Thanks to its forward-thinking architecture, designed not around a commercial business model but around practical utility, data privacy, and digital sovereignty, it offers unique capabilities that set it apart.

🔗Features

With Set-OutlookSignatures and the optional Benefactor Circle add-on, signatures and out-of-office replies can be:

📝

Design & Content

Template Variety: Generated from templates in DOCX or HTML file format.

Rich Variables: Customized with a broad range of variables, including photos and images, from Entra ID, Active Directory and other sources.

Data Scope: Variables are available for the currently logged-on user, the current mailbox, and their managers.

Accessibility: Designed for barrier-free accessibility with custom link and image descriptions for screen readers and comparable tools.

Standardized Formatting: Phone numbers and postal addresses can be formatted by international standards or custom requirements.

Templates Included: Sample templates for signatures and OOF messages demonstrate many features and are provided as .docx and .htm files.

🚀

Deployment & Mailbox Support

Targeting: Applied to all mailboxes (including shared mailboxes(1)), specific mailbox groups, specific email addresses (including alias and secondary addresses), or specific user and mailbox properties.

Outlook Support: Works for every mailbox across all Outlook profiles (Outlook, New Outlook(1), Outlook for the web(1)), including automapped and additional mailboxes(1).

Template Logic: Created with different names from the same template; one template can be used for many mailboxes.

Scheduling: Assigned time ranges(1) within which they are valid.

Defaults: Set as default signature for new emails, replies, and forwards, or as default OOF message(1) for internal/external recipients.

🛡️

Platform, Architecture & Security

Multi-Platform Sync: Set signatures in Outlook Web(1) and mirror them as roaming signatures(1) across Windows, macOS, and Linux.

Flexible Execution: Run via logon script, scheduled task, or as a central service(1)—no client installation or end-user interaction required.

Hybrid Support: Works natively on-prem, hybrid, and in all M365 clouds (Public, GCC High, China, Bleu, etc.).

Add-in & Mobile: Integration for appointments via Outlook add-in(1) and access for mobile/third-party clients via additional paths(1).

Zero-Touch Deployment: SimulateAndDeploy(1) enables full automation without touching the end-user's device.

Data Sovereignty: No telemetry, no "calling home," and no 3rd party data routing; your DNS records and mail flow remain untouched.

Enterprise Scaling: Multi-instance capable and optimized for complex environments with 5-digit mailbox counts.

Security & Testing: Includes simulation mode for safe testing and write protection for Outlook for Windows signatures.

Open Source (FOSS): Set-OutlookSignatures is licensed under the European Union Public License (EUPL). The core engine is peer-reviewable, ensuring transparency and digital sovereignty.

Drafts API Fallback: Supports clients without a signature API by creating centralized HTML/Plain Text drafts(1).

After a certain period of use, the subtle note "Free and open-source Set-OutlookSignatures" is appended to signatures. This tagline can be easily removed(1).

🔗Feature comparison

🔗Pricing Benchmark

Set-OutlookSignatures is and will always be free. What began as a technology demonstrator is now the most secure and versatile open-source tool for managing email signatures. Learn more about the story behind the code.

The Benefactor Circle add-on unlocks advanced features — for just EUR 0.25 per mailbox/month (EUR 3.00 per year). Billed annually, no auto-renewal.

The add-on is an investment that pays off from day one, certainly for you as well!
Facts, not guesswork: Calculate your specific savings in just five minutes with our business case.

Thanks to its unique features and exclusive manufacturer availability, direct procurement in compliance with legal requirements is generally possible without a public tender.

Also consider the total cost of ownership (TCO) over several years. Some competitors include automatic annual price increases of 8% or more in the fine print.

Mailboxes (1 year)
Examples. Buy any amount.		 Set-OutlookSignatures with
Benefactor Circle add-on		 Competitor A Competitor B Competitor C
100 Mailboxes 🟢 EUR 300 🔴 approx. EUR 1,600 🟡 approx. EUR 1,300 🔴 approx. EUR 1,600
250 Mailboxes 🟢 EUR 750 🔴 approx. EUR 4,000 🟡 approx. EUR 2,700 🔴 approx. EUR 3,600
500 Mailboxes 🟢 EUR 1,500 🔴 approx. EUR 8,000 🟡 approx. EUR 4,400 🟡 approx. EUR 6,200
1,000 Mailboxes 🟢 EUR 3,000 🔴 approx. EUR 15,700 🟡 approx. EUR 8,700 🟡 approx. EUR 10,500
10,000 Mailboxes 🟢 EUR 30,000 🔴 approx. EUR 110,000 🟡 approx. EUR 65,000 🟡 approx. EUR 41,000

🔗Detailed Comparison Benchmark

Set-OutlookSignatures with
Benefactor Circle add-on		 Competitor A Competitor B Competitor C
Free and Open-Source core 🟢 🔴 🔴 🔴
Emails stay in your environment (no re-routing to 3rd party datacenters) 🟢 🟡 Optional, causes reduced feature set 🔴 🔴
Is hosted and runs in environments that you already trust and for which you have established security and management structures 🟢 🔴 🔴 🔴
Entra ID and Active Directory permissions 🟢 User (delegated) permissions, least privilege principle, clearly documented and justified 🔴 Application permissions, transfer all directory data, transfer all emails 🔴 Application permissions, transfer all directory data, transfer all emails 🔴 Application permissions, transfer all directory data, transfer all emails
Entra ID and Active Directory data stays in your environment (no transfer to 3rd party datacenters) 🟢 🔴 🔴 🔴
Does not require configuring Exchange adding a dependency to it 🟢 🔴 🔴 🔴
Multiple independent instances can be run in the same environment 🟢 🔴 🔴 🔴
No telemetry or usage data collection, direct or indirect 🟢 🔴 🔴 🔴
No auto-renewing subscription 🟢 🔴 🔴 🔴
IT can delegate signature management, e.g. to marketing 🟢 🟢 🟡 Not at signature level 🟡 Not at signature level
Apply signatures to all emails 🟡 Outlook clients only 🟢 With email re-routing to a 3rd party datacenter 🟢 With email re-routing to a 3rd party datacenter 🟢 With email re-routing to a 3rd party datacenter
Apply signature based on recipients 🟡 Highly customizable, 10+ properties. Same signature for all recipients. 🟡 Internal, external, group membership, email address. Different signature for each recipient via email re-routing to a 3rd party datacenter. 🟡 Internal or external. Same signature for all recipients. 🔴
Additional data sources besides Active Directory and Entra ID 🟢 🟡 🔴 🔴
Supports on-prem and all M365 clouds (public, national, sovereign, hybrid) 🟢 Public, US Government (GCC, GCC High, DoD), China, sovereign clouds Bleu, Delos, GovSG, and more 🔴 🔴 🔴
Supports cross-tenant access and multitenant organizations 🟢 🔴 🔴 🔴
Support for Microsoft roaming signatures (multiple signatures in Outlook for the web and New Outlook) 🟢 🔴 🔴 🔴
Number of templates 🟢 Unlimited 🔴 1, more charged extra 🟢 Unlimited 🟢 Unlimited
Targeting and exclusion 🟢 🔴 Charged extra 🟢 🟢
Scheduling 🟢 🔴 Charged extra 🟢 🟢
Banners 🟢 Unlimited 🔴 1, more charged extra 🟢 Unlimited 🟢 Unlimited
QR codes and vCards 🟢 🔴 Charged extra 🔴 Charged extra 🟢
Signature visible while writing 🟢 🟡 🟡 🟡
Signature visible in Sent Items 🟢 🟡 Cloud mailboxes only 🟡 Cloud mailboxes only 🟡 Cloud mailboxes only
Out-of-office reply messages 🟢 🔴 Charged extra 🟡 Same for internal and external senders 🔴 Charged extra
User-controlled email signatures 🟢 🟡 🟡 🟡
Signatures for encrypted messages 🟢 🟡 🟡 🟡
Signatures for delegates, shared, additional and automapped mailboxes 🟢 🟡 No mixing of sender and delegate replacement variables 🟡 No mixing of sender and delegate replacement variables 🟡 No mixing of sender and delegate replacement variables
Outlook add-in 🟢 No on-prem mailboxes on Android and iOS. Highly customizable with rules, own code and runtime-generated signatures. 🟡 No on-prem mailboxes on Android and iOS, not for appointments 🟡 No on-prem mailboxes on Android and iOS, not for appointments 🔴 No on-prem mailboxes
Support pricing model 🟢 Charged per support hour 🔴 Charged if used or not 🔴 Charged if used or not 🔴 Charged if used or not
Software escrow 🟢 To the free and open-source Set-OutlookSignatures project 🔴 🔴 🔴
Phone number formatting 🟢 E164, international, national, RFC3966, regex, custom 🟡 Regex 🔴 🟡 RegEx
Postal address formatting 🟢 Templates for more than 200 countries/regions, custom 🟡 Regex 🔴 🟡 RegEx
Direct procurement without public tender 🟢 Unique features, exclusive manufacturer availablity 🔴 No unique features, no exclusive manufacturer availablity 🔴 No unique features, no exclusive manufacturer availablity 🔴 No unique features, no exclusive manufacturer availablity

(1) Some features are exclusive to the Benefactor Circle add-on.

The Benefactor Circle license funds the open-source mission, ensuring the core engine remains free and peer-reviewable for the global community.