Selecting a CRM

Customer is looking for a CRM to handle transactional emails with customers, management of short term and long term tasks from those interactions, and potentially billing/invoicing.

He wants to use Monday.com but I don’t believe that covers transactional emails. He’s currently hitting GMail sending limits from a shared Inbox.

I was thinking potentially integrating a Zendesk account to handle emails, with the type of collaborative project tool he’s looking for like a Monday or a Clickup.

I’m asking because I wonder if there are any tools out there which could handle all of this. (Aside from Salesforce, which he’s apparently banned from due to breaking a contract.)

Thanks!