How to solve the problem of signatures not added to emails in Office 365?

Sigsync Email Signatures are not inserted to an email conversation.

Wrong signature mode selected

Sigsync has three signature modes of adding signatures (server-side, client-side and mixed). While Sigsync Email Signatures for Office 365 operates in server-side mode, the client-side signatures will not work (and the other way round). For example, the server side mode requires you to configure connectors and the client side mode works after you install the Sigsync Signatures Outlook Add-in. Both the server-side and client-side signatures work in mixed mode. If your signatures are not included in the emails as expected, ensure that you have chosen the proper signature mode.

You can check which mode is currently selected by following the steps below.

  1. Login to Sigsync Dashboard. Under Connectors Configuration you can see the Pending status. This means that you have not configured the connectors.

    Check Connectors Configuration

Click here to know how to configure Exchange Online Connectors.

Know the details of signature modes.

Office 365 tenant is not registered with Sigsync services

Tenant registration is necessary for Sigsync Email Signatures to operate in each of the modes. If the signature is not inserted to messages sent by any user, ensure that your tenant is not deregistered or that it has not been blocked for any reason.

To verify your tenant status, login to the Sigsync dashboard and verify if your tenant is visible in the list. If not, you have to register it. To register, click on the Add more tenants button and follow the steps to add a tenant.

Click here to Register Office 365 Tenant.

Your free trial period or subscription has expired

If your trial version or your paid subscription plan has expired, your signatures will not be added to your emails. You can renew the subscription and continue to use the service without any interruptions. Contact Sigsync support for the details.

To check your subscription status login to Sigsync Dashboard and click on the 'Subscriptions' < 'Manage Subscriptions'. Select the Tenant and click the 'Buy Subscription' button to proceed with the renew subscrition

Click Subscription from the Dashboard

You have exceeded the number of Sigsync licenses

If a signature is not added for all users and only some users receive a signature, then you might have used up all of the available licenses or configured the connectors incorrectly, i.e., the sender's list is too long and exceeds the number of licenses purchased.

To check the used license count, refer to the link below.

To know how to enable signatures only to specific Active Directory groups, refer to this link.

Sigsync configuration is not complete

If you have added / removed users in Office 365 or changed users attributes in Office 365 and it's not reflecting in Sigsync, then you can sync the AD attributes by clicking the 'Sync AD Changes Now' button in the Sigsync 'Settings' tab.

Sync AD Changes in Sigsync Preferences

Access Token Expiration

Usually Access tokens don’t expire, but there are few cases that may cause the tokens to expire. Example, if you change any of the following credentials like, password of the global admin, authentication method of admin account, security setting in your organization and MFA service setting for trusted devices. If the tokens expired, you need to Sync AD attributes.

Unsupported message type

For a few email types, signatures will not be added.

In client-side mode, signatures will not be added to encrypted or IRM (Information Rights Management) protected messages in Outlook on the web.

In server-side mode, encrypted/digitally signed messages will be sent with signatures only if encryption takes place after these messages pass through the Sigsync services.

A signature rule does not match the conditions/exceptions set for a message

When you create a signature rule, you can set rules based on specific senders, senders from a group, or apply the signature to all the senders. The rules can also be customized to filter the emails based on keywords or based on the recipients whether they are internal or external to the organization. If your signatures are not added to your email, review the Senders, Recipients and Keywords conditions to make sure that the message fulfils all of them.

Signature issues with Server side mode

You have not configured Sigsync connectors

Inbound and outbound connectors configuration is required if you want to use Sigsync Email Signatures for Office 365 in server-side or mixed mode configuration.

To know more about connectors configuration, refer to the link below.

Sigsync’s connector configuration does not include a message sender.

This issue will occur if the sender’s group you selected at the time of signature configuration is not matching with the senders added in the signature rule.

If you see the Signature configuration (as shown in the image below), an Admin group is selected whose emails should be routed through Sigsync email Azure service. When the users send messages, Sigsync will check them against your signature rules and add signatures only to emails that match the condition defined in these rules.

Enable signature to Admin groups

As per the signature rule (shown in the image below), All senders should get email signatures except support groups, but only mails from the Admin groups are routed via Sigsync Email Azure service to get signatures as per the connectors configuration.


To fix this issue, redo the signature configuration for the senders to whom you would like to attach email signatures. For more details, refer to the link below.

If you would like to learn more about manually adding and removing groups and users, refer the link below.

Signature issues with Client side mode

Unsupported Outlook version

Client-side signatures will only be included in emails sent from the Outlook desktop app for Windows, Version 2013 or new ones. Make sure that users in your company use supported versions of Outlook.

If Sigsync Signature Add-in is not present in Outlook, you can install it by following the steps below.

You have not restarted Outlook

You need to restart Outlook after the first login and later. Whenever any signature is set to default, or modified, the add-in will prompt to restart Outlook. If you do not restart Outlook, the signature will not be added properly.

Signature issues with Mixed mode

Identifying problems with server-side and client-side signatures

In Mixed mode, first we have to identify whether the problem is a server side or a client-side mode, as mixed mode is a combination of server-side and client-side.

Add-in installation by unauthorized users

The Sigsync Signatures Outlook Add-in can be installed individually by a user or centrally from the Integrated apps or Exchange admin center. Refer to the link for more details about the installation.


Streamline Email Signature Management with a Free On-demand Demo from Sigsync

Sigsync email signature service provides effortless, centralized signature management for Office 365 and Exchange. Our team can assist you in quickly setting up company-wide signatures. Request a free on-demand demo to see how Sigsync can simplify your email signature management process.


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