You can manage the contacts for your vendors and customers from their Company profile page under the About tab. Here you will see a list with the contacts that have been added for that company.
On the right side there is a “...” button and when clicked you have the option to Edit or Archive the contact.
Clicking Edit will reveal a slide out on the right side where you can edit the contact’s:
Just make sure you click Update contact to save the changes.
Archiving and Unarchiving Contacts
Clicking Archive will disable the contact from receiving any email communication from that point forward. You can Unarchive a contact by clicking the “...” again and selecting the option from the menu.