An email signature service become most worthy when it enforces the centralized management of signatures for all the employees and ensures a low-cost.
Sigsync is a secured, centralized Office 365 email signature service that holds well across all the email clients and devices.
Office 365 Email signature software supports company branding by including the organization logo, social media icons, any other links and mobile apps links that gives brand acknowledgment to your organization. It helps to add your company promotional products, services and events in email signature area. This will greatly help you in managing your email signature campaign effortlessly.

Few highlighted features:

Quick configuration of Office 365 email signature using automatic wizard
Tamper-proof, centralized secured email signature service
Branded dynamic signatures for any department or individual
Professional email signature templates for the specific requirement
Automated drag and drop HTML signature generator
Various social media icons
Active directory integration to retrieve contact information
Option to include web analytics and One Click survey