All Outlook data is contained in a single PST file (unless you are running
against Exchange Server). There is no separate file for Contacts. As a
result, trying to email an Outlook data file can be problematic since they
are usually 10-100 MB or more in size.
If you only need your Contacts you could create a separate PST file and copy
your Contacts into it, then email that as an attachment, but it will still
likely be several MB in size.

Try exporting your contacts to a csv file for windows it is a smaller
format. But take into account if your on a exchange then due to the security
feature of a exchange server the address will not function properly at home.