Can Zoho do it all?

Can Zoho do it all?

I am on a Mac platform.  I am currently using:
- Salesforce.com as CRM
- ConstantContact for email marketing (monthly newsletter to various groups)
- Entourage for email
- Excel for accounting

I would like to use:
- Zoho for CRM, email marketing and accounting/invoice
- Mac mail for email (able to synchronise with Zoho CRM)

Is this possible?
If not, which parts should be handled by another service?


Thanks for any insight
Laurent