This article provides instruction on how to add hyperlink to a signature using Markdown. All other Markdown formats can be used in a signature such as images and code blocks.
Must have at least an agent access to your Zendesk Support account.
1. Click View profile.
2. In Signature, key in your Markdown text.
e.g. [Link display text](http://www.zendesk.com)
3. When an agent replies to the email, the signature will appear as shown in the image below.