RealmJoin provides a default package for Outlook signature files. Those files can be found in:
%userprofile%\AppData\Roaming\Microsoft\Signatures
.\anyname.txt
.\anyname.htm
The following fields for signatures are extracted from the Microsoft Graph API and may be used:
Graph_User_BusinessPhoneGraph_User_CityGraph_User_CompanyNameGraph_User_CountryGraph_User_DepartmentGraph_User_DisplayNameGraph_User_GivenNameGraph_User_IdGraph_User_JobTitleGraph_User_MailGraph_User_MobilePhoneGraph_User_OfficeLocationGraph_User_PostalCodeGraph_User_StateGraph_User_StreetAddressGraph_User_Surname