Configuring preferences and options in Outlook.com
Hello Lionel,
We apologize for the delayed response. We have checked the information you provided and determined that it's possible that you encounter this issue with the picture in your email signature when sent via Outlook.com because it is being blocked by the spam/junk filter. We suggest that you get in touch with the email recipients and advise them to add your email address to their contact list. Afterwards, try to send them an email again to check if this has resolved the issue.
Let us know how things turn out.
Thank you.