ExtendSync for Outlook NetSuite users can add an unlimited number of attachments from an email at the same time, however, only files that are 10MB or less will be accepted by Netsuite.
Keep in mind!
For an email, the individual attachment file that is supported is up to 10 MB.
The total email size limit should not exceed 25 MB.
Support for more and larger attachments
Our Enterprise Edition customers can continue to leverage our OneDrive for Business and SharePoint integration to include file attachments up to 150 MB in size and to associate files up to 250 GB (yes GB) in size with NetSuite records.