Need a branded email signature template for the whole team

Our company is growing and right now every employee uses a different email signature — some have outdated logos, some have no signature at all, and formatting breaks depending on which mail program they use. We want to fix this once and for all with a single professional template that everyone on the team will use going forward.

The template needs to include our logo, employee name and position, contact details, and a small block of social icons, in a clean modern layout matching our brand colors and fonts. It's important the signature looks correct not only in the most common desktop mail program but also in webmail and mobile apps, since our staff work on different devices. We've had signatures break before — images not loading, spacing collapsing, fonts changing — and we don't want a repeat of that.

Besides the design itself, we need clear step by step instructions, ideally with screenshots, explaining how to install the signature in popular mail clients, so non-technical staff can set it up themselves without asking IT every time someone joins the team.

What we expect from the final result:
— one master template plus a couple of minor variations for different departments
— source files that stay editable for future updates
— tested rendering across at least four major mail clients
— a short installation guide written in plain language