Office 365 (Thunderbird) - Set a vacation message (out of office)
Thunderbird has no native support for Vacation/Out of Office Messages
However, you can configure your email account through the Outlook Web App to send a Vacation Message to all incoming messages.
Please click here to learn how to set a Vacation Message with the Outlook Web App.
For more on why Thunderbird has no native support, please click here.
For more on why Thunderbird has no native support, please click here.