Using older versions of Outlook for Mac for personal email and calendar
Hello Joël Lagneau**,**
Good day! Thank you for reaching out to Microsoft community.
As per your description, it seems like that you're trying to add an email signature to your account, but your email address (****@interchanvre.fr) doesn’t appear in your account settings, which is preventing you from setting up a signature. You're currently using the Legacy Outlook for Mac version.
Regarding the DNS records of your domain 'interchanvre.fr', your MX is not pointed Microsoft exchange online server. It seems like you do not have a Microsoft Exchange account.
As you know, all the data for your emails and configuration depends on the server where your email is hosted, you may need to reach out to them since we do not support 3rd party account.
I will suggest talking with you IT administrator of your organization, they can assist you getting in contact with email hosting provider.
Microsoft community is here to help with the information you need or issue you are facing regarding Office 365 products.
I hope this helps. Let me know if you have any further questions or concerns.
Thanks for choosing the MS community and have a great day ahead!!
Sincerely
S M Nazmun Nur | Microsoft Community Moderator