Gmail a #1 Choice for email
I know you don't want to dump your aol.mail, HotMail, or Yahoo Mail, etc. And using your ISP's email like Optonline, or Comcast, is actually not a great idea..
Consider this. Gmail has the best spam filters and Gmail can fetch your other email.
The advantage of having a Google Account (Gmail).
If you are routinely asked to share something from someone's Google Drive, like a document to edit, or a spreadsheet to share information on, then you would have secure way to do that since the document that is shared to you, will appear in your own Google Drive and can be edited (if you have been granted editing rights. Otherwise, you may have only Viewing Rights.
You can actually still use your other email and have Gmail fetch it for you. Or conversely, you can have your old email Forward everything to your new Gmail Account. You can then keep the old email address but never send from it anymore. People with your old address can still get you. You can add a signature to your Gmail to tell people that you are phasing out the old address. But since Gmail will be Fetching your old email, those who have your old address will still get you. You won't have to worry that that email from an old friend you haven't heard from in years, can still contact you. Or maybe an online merchant has the old email address and you have forgotten to update that site's information.
Watch this video with some explaination :
Sign up for a Google (gmail) account
Using other emails Search on The Tech Guy website