Email Signature for Outlook

An email signature for Outlook is configured in one of four ways depending on the deployment scope. Individual users set it in Outlook under File > Options > Mail > Signatures, where they create one or more signatures and assign them to new messages or replies. Microsoft's native Roaming Signatures (generally available since 2023) stores those user-set signatures in the Exchange Online mailbox so the same signature appears in Outlook desktop, web, and mobile. For organization-wide deployment, IT administrators use either a centrally deployed Outlook add-in that injects the signature at compose time (preferred for dynamic personalization and visibility in Sent Items) or an Exchange Online transport rule that stamps the signature at the server before delivery (preferred for catch-all coverage including mobile and third-party clients). The Outlook desktop application has historically rendered HTML using Microsoft Word's engine, which lacks support for modern CSS, so signatures must use table-based layouts with MSO-conditional fallbacks for reliable rendering.