How to Set Up Email Signatures in Microsoft 365

Nothing says 'we haven't got our act together' like everyone in the company having a different email signature format. Some have the logo, some don't. Someone's still got the old phone number. One person's is in Comic Sans.

Here's how to sort it out in Microsoft 365.

Option 1: Individual signatures in Outlook

The simplest approach. Each person sets up their own signature in Outlook → Settings → Mail → Compose and reply.

Give your team a template to copy and paste. Include: name, title, phone, email, website, and the company logo hosted online (not embedded — it bloats every email).

Downside: you're relying on people to use it correctly and update it when things change.

Option 2: Centralised signatures via Exchange

This is the better approach for businesses. You create one signature template and Exchange automatically adds it to every outgoing email.

Go to Exchange admin center → Mail flow → Rules → Create a new rule.

Set the condition to 'Apply to all messages sent to outside the organisation'.

Set the action to 'Append a disclaimer' and paste your HTML signature template.

Use dynamic variables to personalise it: %%DisplayName%%, %%Title%%, %%Phone%%, %%Department%%. These pull from each user's profile automatically.

Designing the signature

Keep it simple. Name, title, phone, email, website. Maybe a small logo. That's it.

Don't embed images — host the logo on your website and reference the URL. Embedded images add 50-100KB to every email and get blocked by many email clients.

Use a maximum of two fonts and two colours. Match your brand. No inspirational quotes, no legal disclaimers longer than the actual email, no social media icons that nobody clicks.

Make sure it looks good on mobile. Most email is read on phones now.

Keeping them updated

If you use the centralised approach, update the template in one place and it changes for everyone.

Make sure user profiles in Entra ID are up to date — the dynamic variables pull from there. If someone's phone number is wrong in their profile, it'll be wrong in their signature.

Review signatures when people change roles, when the company rebrands, or when contact details change.

We can set up centralised email signatures as part of your M365 managed service. One template, consistent across the business, updated in one place.