How to Set Up an HTML Email Signature in Microsoft 365?

I’ve done this for our users, and unfortunately, if you want a unique signature for each one, you'll have to set them up individually - no bulk options available. The good news is that you don’t necessarily need to host images online; they can be included inline and attached to the email. Just be wary of potential issues with iOS devices; sometimes, they can mess up the inline images and display them as broken links.

As an admin, you could apply email signatures to all or specific users through mail flow rules. Microsoft has guidance on this, which you can find in their admin documentation.

I would strongly recommend using Exclaimer for this. It simplifies everything and saves you from the headache of managing signatures through Microsoft 365. Plus, as a side note, I’d ditch the logo. Signatures with images tend to cause more trouble than they're worth!

For managing signatures effectively, consider using a tool like Signitic. Otherwise, you're looking at making a template and having users set it up themselves, which can be a hassle.

In our company, we keep a Word document for the signature template and logo saved on the network. Users just copy it into their Outlook and update their details. Providing a quick guide on how to apply it can be a huge help too! Just a heads up, though - if you're enforcing signatures via Exchange, you'll likely need to host the image.