Email Clients, a/k/a Programs
Apps that let you read your mail
There are two kinds of email clients. One gets installed on your computer; the other, webmail, is in the Cloud - so most of us were "in the Cloud" long before cloud storage became readily available.
I prefer a client installed on my PC so that I can backup my email data as I would any personal data files. But the real benefit of webmail is that messages can be accessed from any computer or device that has a web browser and it takes up no space on your computer or mobile device.
Note that some older versions of Outlook, Windows Live Mail are considered too vulnerable by certain email providers, especially if they run in POP3 mode.
Thunderbird is my top choice for an email client. From the same folks who crafted Firefox.
It gathers email from most of my email accounts. Yes, I have a handful of email accounts. Much of it is for catching junk mail. Mostly, it is to protect my personal account that is otherwise reserved for friends & family.
Outlook - it lives, but only in the Business or Pro versions of Office, no longer in the Home & Student versions of Office. Many rely on Outlook since it integrates Contacts and Calendars.
Windows Live Mail - replacement for Outlook Express, it comes with Windows 7, can be downloaded for free along with MovieMaker and other Live apps and will install & run under Windows 8.
SeaMonkey - an interesting alternative that includes its own web browser. Began life under the Mozilla Foundation and still shares some code from Thunderbird.
Outlook.com - is Microsoft's replacement for Hotmail; it is webmail, free, but requires a "Microsoft Account." Will work with most variants of Microsoft email domains: hotmail.com, outlook.com, live.com, etc.
Gmail - email from Google. My choice for my personal email. It can be configured with an installed email client. Has an excellent spam filter built in, although I do notice some valid advertisement emails from vendors I've used land in Spam.
The Contacts from Gmail link directly to Android phones and can be used to back up iPhone contacts. So Gmail Contacts also holds my address book info - phone numbers, addresses for real mail and actually getting there, free-form notes, etc.
While not directly integrated into Gmail, the Google Calendar is my choice for my schedule.
aol.com - Still out there. Feeling a bit retro? Want to hear, "You've got mail!"? An AOL account is not necessary to sign up for a new or continue using your existing AOL email account.
Free when using web access or a web client.
Comcast.net or Verizon.net, etc - Most Internet service providers (ISPs) offer free email accounts.
Their versions of webmail often leaves alot to be desired (I personally dislike using Comcast's webmail, but if I absolutely need it at least I can get to it) and can be avoided by using an email client, such as (older versions of) Outlook, Thunderbird, SeaMonkey.
YourDomain.com - If you have a personal or business website, then you probably have email accounts for those websites, too. Often the website clients are out-dated and often don't function properly. Like ISP-email accounts, email clients and even Webmail clients like Gmail.com and Outlook.com can be configured to send and receive email for/from these accounts.