Alternative to sharepoint list to share outlook contacts?

Hey guys,

We currently host our vender contacts as a list in O365 sharepoint that we sync to Outlook. The list has over 15,000 items, so you can't even scroll through it without setting up multiple views. Additionally, there are compatibility issues between Outlook and Sharepoint -- for example, in Outlook, if you put in a contact's website as www... and not http://www..., the contact will reject from sharepoint, and end up in limbo.

I was wondering if any of you guys have a similar situation and can suggests alternatives to our current setup. Thanks.