If you're seeing an error when you're trying to send an email, it's likely due to the Synergy Client not being able to connect with the SMTP server.
Hosted clients
If your environment is hosted by us, simple raise a new case online and reference the title of this article. Ensure to include any information on the message you're trying to send.
Non-hosted clients
If you're self-hosted, you can check your mail settings.
Click System Manager.
Click Options, then click Common.
Click Mail Settings and check what is filled in under SMTP Server and SMTP Port.
You can then ask your IT to check if a connection can be made from the machine Synergy is installed to the SMTP server using these details.