Office 365 (Web) - Create a Signature File
Your signature can be added automatically to all outgoing messages, or you can choose to add your email signature only to specific messages.
If you use both Outlook via the web and the Outlook Client, you need to create a signature file in each as they don't transfer from one platform to the other.
In this article
Manually add your signature to a new message
Automatically add your signature to every message you send
Create a signature
1. Sign in to Outlook Web App.
2. On the nav bar, choose Mail.
Or
Choose App launcher 
> Mail.
3. On the nav bar, choose Settings 
> Options.
4. Under Options, choose MAIL > Layout > Email signature.
5. Under Email signature, in the text box, type the signature you want to use. Use the formatting mini toolbar to change the appearance of the signature.
6. If you want your signature to display at the bottom of all outgoing items, including replies and forwards, select Automatically include my signature on messages I send. If you don’t select this option, you manually can add your signature to any message.
7. Choose Save.
Manually add your signature to a new message
If you've created a signature, but didn't select the option to add your signature to all outgoing messages, you manually can add it to specific messages.
1. Sign in to Outlook Web App.
2. On the nav bar, choose Mail.
Or
Choose App launcher > Mail.
3. Choose 
above the folder list. A new message form opens in
the reading pane.
4. At the top of the message, choose Insert 
> Signature (or Your
signature).
5. When your message is ready to go, choose 
Send.
Automatically add your signature to every message you send
If you've created a signature, you can specify if the
signature is added to all outgoing messages, including replies and forwards.
1. Sign in to Outlook Web App.
2. On the nav bar, choose Mail.
Or
Choose App launcher > Mail.
3. On the nav bar, choose Settings > Options.
4. Under Options, choose MAIL > Layout > Email signature.
5. Under Email signature, do one of the following:
- To include your signature at the bottom of all outgoing items, select the Automatically include my signature on messages I send check box.
- To exclude your signature from showing at the bottom of all outgoing messages, clear the Automatically include my signature on messages I send check box or simply delete the signature from the body of your message.
What else do I need to know?
- You can’t include an image file (such as a .gif or .jpg) with your signature in Outlook Web App.