I have a few questions for anyone who may use this app...
Is it safe?
Can I use and older "hotmail" account on it?
Do I use the same password or create a new one?
Yes it is safe and considered the best way to check your email on the go. You can use almost any email so yes, hotmail is good to go for it. You verify your accounts to use them.
Oh yes it is safe. I don't use it myself because I never link my main email account to my phone. I am too paranoid about losing it or it getting hacked. I have too much linked to it BUT this app does help.
When you login you use your email and your email's password. There is no separate password. This is the only reason I never used it. I am not giving out my password to some app.
It is one of the best apps and it is safer than using your standard email on your phone. I like it. Makes it super easy to keep up with work messages and I am able to organize everything. Worth giving a try.