This article applies for Axigen X1 (10.1.x) to X3 Update 1 (10.3.1).
Starting with Axigen X3 Update 2 (10.3.2), the webmail customization is done via SASS.
This article does not treat branding (i.e. using your own logos and brand name instead of the default ones) — it goes a step further and describes how to make additional changes to the WebMail to match your desired appearance. For branding only, here's a detailed article on branding your WebMail interfaces directly via WebAdmin.
You can customize your WebMail appearance by modifying the WebMail html and css files in /webmail/.
Information on how to prepare the WebMail service for skinning and customization can be found in our related article: https://www.axigen.com/kb/show/132.
This article assumes that you have the necessary HTML and CSS knowledge to safely make the customizations described below.
Please note that WebMail customizations do not make object of support. In addition, we strongly recommend you to make and keep a backup copy of the files you're altering.