How to create a signature in Outlook In a new message, choose Signature >Signatures. On the Email Signature tab, choose New. Type a name and update signature, then choose OK. Under Choose default signature, do the following: In the New messages list, choose the signature that you want to be added automatically to all new email messages. If you don't want to auto sign your email messages, you can ignore this option as (none) is the default value. In the Replies/forwards list, choose the signature that you want to be added automatically (auto sign) when you reply to or forward messages.