Seperate databases?

I am just now getting involved in the whole web database thing and had what I assume is a pretty general question. I am working on a couple of scripts in php that use access to a database to store everything from customers emails for a newsletter to news stories for a section on the site. Here's my question.

Should I have two seperate databases, one for emails, and one for newsletters, or is all the information really on the same database on the server, but just seperated by identifiers and such breaking the information down into groups on a single storage unit? I am using mysql.

Thanks,
Sean

It'll all be on one database server, so the easiest thing to do is just create tables under different names, then go about your script building as usual and nobody will know the difference.

BTW, if it's all for the same business then you never know when the two sets of data may actually be needed together!