Just to go against the crowd: I really don’t like Gmail… I prefer Outlook. Its layout is so clean. Its “sweep” functions make organizing easy—I move something to a different folder once, and future emails/already-sent emails can follow suit. I can forward all my other addresses to the Outlook account, and then send “from” the other accounts while still in the Outlook account. I think I can make as many accounts as I need (honestly I haven’t tried but I don’t see why not), but I don’t need to, because I can make and delete aliases as needed—a separate address to the same inbox. I also really appreciate using Office Online instead of the Google options (because the Google version of Word always messes up formatting/etc. when I inevitably have to download the documents)... if other email addresses have those features, then I guess oops, but I’ve never found them.
But for just a “just need the address” account, for whatever reason I think “Gmail” too.