Hi from the team at Symprex, and happy Thanksgiving to our American customers.

Our development team have been completing multiple bug fixes across the Portal, Add-in, SMTP services; Our SMTP infrastructure has been cleaned up and modernised — with improvements in backend performance, reliability, and deployment pipelines; resulting in a more robust and reliable SMTP service.

🛠 Other Enhancements 

Improvement - We now fully support UTF-8 local-part email addresses
Improvement - SMTP: We've made several improvements to handling of non-standard mail addresses and load scaling
IMprovement - Portal: Groups and users in Rules are now shown in a consistent (alphabetised) order, so you see them in the order intended
Improvement - Portal: A new Portal setting lets organisations decide whether “Send Pictures with Document” is enabled for each user’s device in the Agent
Bug fix - Portal: We've made several bug fixes to localization text descriptors
Bug fix - Portal: We've fixed a bug preventing selection of groups
Bug fix - Add-in: Ensured Add-in disabling via platform is honoured even when rules don’t match the user
Bug fix - SMTP: We've resolved an issue where multiple matching domains can stop mail sending
Bug fix - Portal: Selecting “All Signatures” now works as expected without showing unnecessary dialogs for Campaigns and Disclaimers
Bug fix - Add-in: We've fixed an issue due to Outlook blocking certain image formats

Hi, and welcome to the Signature 365 release update for October.

Our development team has made significant improvements to the reliability and resilience of our core systems since the last update. These changes make it easier to detect and respond quickly to anything that might affect performance, helping ensure a smoother overall experience.

We’ve also rolled out several enhancements to our server-side infrastructure, including the services that handle email delivery and logging. These updates improve consistency, scalability under load and visibility for our support and operations teams — all contributing to faster, more dependable mail delivery.

 As usual we have also resolved a number of bugs and added additional enhancements to the service as detailed below.

🛠 Other Enhancements

Improvement Import: Changes to user photos are listed in the import overview
Improvement Server-side: We've implemented systems limiting disruption caused by unintentional mass emails from customers
Improvement Import: Deleted Entra ID groups are now highlighted on import configuration

Bug fix Portal: We've fixed an issue where the imported user count could be incorrect.
Bug fix Import: We've fixed an issue where an upload failure can cause import to fail

Hello again - we hope you have enjoyed a great summer!

The team have been hard at work since our last update, working on several internal improvements to greatly enhance our resilience and recovery processes for all server-side email, ensuring we can continue to process your server-side emails at all times.

Keyboard shortcuts and Tabbable selections

We've introduced the ability to tab between add-in sections, and the feature to use Ctrl + num to select a signature by keyboard shortcut from the taskpane:

As usual the team have also been busy with the additional improvements and fixes detailed below.

🛠 Other Enhancements

Improvement - Fields: We've increased the allowed organisation field value size to 1000 characters
Improvement - We've clarified the instructions for users when using 2FA recovery codes
Improvement - Outlook Add-in: We've enabled tabbable selections and keyboard shortcuts for signatures in the add-in task pane
Improvement - Improved Sent Items Update to more reliably find the email to update 

Bug fix - Portal: We've fixed a bug in language preferences which prevented users from being invited as a teammate
Bug fix - Portal: Rule priority order value can appear out of sync in the UI
Bug fix - Template Editor: If empty / else menu option does not include the "!"
Bug fix - Partner Billing: We've fixed a bug where an owner account email has a leading space

We’re thrilled to roll out language support for the Signature 365 portal and add-in — now live in production!

You can now experience Signature 365 in your preferred language, with support for:
Dansk, Deutsch, English, Español, Français, Italiano, Norsk, Nederlands, Português, and Svenska.

This is a major step toward making Signature 365 more accessible and user-friendly for teams around the globe. Dive in and explore it in your language of choice!

Signature 365 Portal

Language selection in the Signature 365 portal is manual, and will default to English. To update your language in the portal, click your name drop-down in the top right and select an available language from the Language menu. The language selection for the portal will persist across logins and also update your Outlook add-in to match.

Signature 365 add-in

By default, the Signature 365 add-in will auto-detect the user's Outlook language, and use this where possible to apply the correct language. Where the Outlook language is not yet supported in Signature 365, we will default to English or the language selected in the portal.

Users can update the display language of the add-in if required by opening the task pane and selecting the Settings tab, which gives the option to select your desired display language. Selecting a language from the drop-down and clicking the Save button will save this setting. The option will persist across logins and across all Outlook platforms.

Hi from the team at Symprex!

Following the implementation of NAA authentication by Microsoft in February, we are seeing the disabling of legacy tokens on increasing numbers of customer Microsoft 365 tenants - this process is expected to be completed my Microsoft in June.

A very large percentage of customers have already completed the upgrade to the latest version of the add-in which we detailed in February. If you are already on v3, or joined Signature 365 after February, no action is required.

If the decision was made to enable legacy tokens and delay the upgrade, its is of utmost importance that the process is now completed and the upgrade is applied. Once legacy tokens are fully disabled, the previous versions of the add-in cannot function, and users with the Outlook add-in will not receive signatures until this is completed.

Details on the update process are noted here: Nested app authentication (NAA) and deprecation of Exchange legacy tokens


If you have any questions on the process, please contact our support team.

Hi from the team at Symprex!

We are happy to announce a number of new features introduced to Signature 365 in the last month, including the scheduling of disclaimers and additional Outlook settings.

Disclaimer Scheduling

Following requests from customers, we have introduced the ability to schedule the disclaimers applied to your signatures. The scheduling process works in the same method as campaigns, allowing disclaimers to be applied at a future date, and expiring when desired. As with signature rules and campaigns, disclaimers are applied in priority order, which can be updated using the "Reorder" button.

Following feedback from our Signature 365 agent customers, we have introduced the ability to change how the Signature 365 agent applies signatures across Outlook profiles and accounts.

These options can be found within the "Outlook (Classic)" integrations card. The defaults are as they have always been, to set for all accounts but not all profiles. Version 2.3.2 or later of the agent is required for these options to take effect. See How to install the Outlook (Classic) agent : Signature 365 Help Center for more information on this.

The team has also been busy with the additional improvements and fixes detailed below.

🛠 Other Enhancements

Improvement Injection: We've improved and added new mail clients to our email text separator detection.
Improvement We've improved the Database connector import to better handle errors, support Windows FIPS and adding scheduling.
Improvement We've improved our error messaging in the task pane when NAA authentication fails.
Improvement Outlook: We've updated and improved the diagnostics panel in the add-in.
Bug fix Portal: Using the "Change Folder" dialog no longer generates an error.
Bug fix Outlook: Legacy tokens being disabled no longer causes the add-in to hang in Outlook Classic event-based activation.
Bug fix Portal: Exporting active users for very large customers no longer times out.
Bug fix Portal: We've fixed an issue where Editors could not load domains.

Hello again from the team at Symprex!

📣 Folders for Signature, Campaign and Disclaimer templates

The team are excited to release the Folders functionality to help with the organisation and management of templates in Signature 365.

When you create a folder structure, this will apply to Signature, Campaign, and Disclaimer templates, displaying it consistently across all template types. You can create templates in folders and drag existing ones into folders and subfolders for easier management.

Your existing configuration will not be affected by this change, and the look and functionality of the portal will not change until a new folder is created.

You can read more about these changes in the article below:

Using folders in Signature 365

Hi again from the team at Symprex!

We have been working hard to ensure as smooth an upgrade as possible for all users of our Outlook Add-In to support the new authentication mechanism from Microsoft, Nested App Authentication. This has now been deployed by over 50% of Signature 365 tenants.

An update email was sent to all Signature 365 administrators advising of these changes in mid-January, Microsoft has recently updated documentation to define legacy disablement as the 17th February 2025.

For our customers that have not yet updated please note that this is a required change mandated by Microsoft if you are utilizing the Signature 365 Outlook add-in. If this is not completed, the add-in will stop working when legacy tokens are disabled by Microsoft. You can find information about upgrading in our Knowledge Base.

We have of course been working on additional fixes and improvements to the platform over the past couple of months, these are detailed below.

🛠 Other Enhancements

• IMPROVEMENT- Resolved timed-out user invites issue in the Partner Portal.
• IMPROVEMENT- You can now select multiple users or groups when creating or editing a rule in the portal.
• IMPROVEMENT- Customers are now able to cancel auto-renewal on their own.
• IMPROVEMENT - We refined the Campaigns view to give more information at a glance.
• IMPROVEMENT - vCards has exited the beta stage.
• IMPROVEMENT - Improved the responsiveness of search across the portal.
• IMPROVEMENT - Updated SMTP text replacement rules for better built-in signature replacement.
• IMPROVEMENT- Handle flakey network conditions better in the Outlook Add-In.
• IMPROVEMENT- The minimum requirement set has been updated for Outlook to 1.10, removing support for Outlook 2016 and 2019
• IMPROVEMENT- Active user CSV export now includes the current add-in version to track add-in deployment.
• BUG FIX- When assigning users to rules, the "Choose" dialog now remembers selections.
• BUG FIX- We've improved the identification of sent items to update in the sent-items-update, leading to improved item update rates.
• BUG FIX- SSO: case matching is too prescriptive for SSO logon causing issues connecting to Microsoft 365 accounts.
• BUG FIX - Plain text signature preview is incorrect in the Outlook task pane.
• BUG FIX - Add-in: Cannot reselect default signature if rule is set to None.
• BUG FIX - Campaigns incorrectly show as expired with an expiry date set.
• BUG FIX- Outlook Add-In dark mode is now supported on Mac.
• BUG FIX- Rule search is no longer case-sensitive.
• BUG FIX- Domain checks now correctly evaluate multiple MX records.

Hello again from the team at Symprex.

Our teams have been working hard to prepare for Microsoft's launch of a new method for Outlook add-in authentication called nested app authentication (NAA). NAA replaces the current authentication method, which Microsoft now refers to as "legacy tokens".

The preferred solution to this change is to upgrade the add-in to version 3.0. This will ensure that you are using the latest version of the add-in, and are able to take advantage of the newest updates and features.

As part of this process you will be asked to grant admin consent to two new permissions ("Maintain access to data you have given it access to" and "Sign in and read user profile"). This does not grant Signature 365 any additional access to data but is required for NAA to work.

Updating the Signature 365 modern add-in

If you are unable to perform the upgrade at this time, please see the following article for additional options:

Nested app authentication (NAA) and deprecation of Exchange legacy tokens

Hello all!

We're excited to introduce a fresh update to Signature 365 with major improvements to enhance your experience.

🔥 Signature, Campaigns, and Disclaimers Overhaul

You can now quickly see which campaigns and disclaimers are targeting specific groups or users, see when a campaign is scheduled or expired and have quick access to View, Edit or Copy right from the menu associated with each item.

🛠 Other Enhancements

As usual, we have been hard at work on the smaller improvements too

• Improvement Migration to .NET 8: We've upgraded to .NET 8, ensuring improved performance, stronger security, and enhanced reliability.
• Improvement Aptos and Aptos Display: These new fonts have been added to the visual editor, integrating with Microsoft's new default Office font.
• Improvement Quickly Remove Custom User Fields: It's now easier to remove custom field values from any user with just a few clicks.
• Improvement User Activity Insights: See when users were last active directly in their profiles for better management and tracking.
• Improvement Remove User-Specific Signature Overrides: Quickly delete signature overrides for individual users, streamlining signature management.
• Improvement More details in the Active User CSV export: You can now see the details of client types a user has accessed, making tracking adoption across Outlook platforms and server-side injection easier.
• Bug fix Alt Attribute Fix for Campaign Images: We've fixed an issue where "alt" attributes weren't added to campaign tracking images, reducing the risk of spam detection issues.