I've just installed Sugar CRM Community - trying to get my head round it all

I'm reading the manual as we speak, but had a few questions I was hoping other could answer for me in the meantime:

1. Adding a new customers - how do I check if the same customer already exists?
I will have a small team of volunteers making contact with prospective customers - and don't want to have duplicate contacts

Is there something in Sugar that checks for duplication?
Let's say 2 users input the same client with slightly different spelt names, but have the same contact number - will the system picks this up and flag or something??

2. Email: I use google applications. For sending, I'm sure it's OK to send out one at a time

But, how about mass sending? I assume Google doesn't like this and stops it?
How do I overcome this? use another domain?

Thanks!


Omar