Hi @Peter Munt
Thanks for reaching out.
SuccessFactors to Micrsoft Entra ID mail attribute is not directly supported in user provisioning.
The mail attribute is linked to M365 license, and when M365 license has been assigned to user using dynamic group or lifecycle workflow, then a mailbox is automatically provisioned for the user and the assigned UPN value is used to set to the mail attribute.
Alternatively, if you're attempting to configure a personal email in the user profile, please make use of the "otherMails" attribute.
Hope this will help.
Please remember to "Accept Answer" if answer helped you.