Pros of Gmail: What is good about Gmail?
Here are some reasons why some people use Gmail.
1. Lots of space. Gmail offers you 7 GB of storage.
2. Gmail is fast performance.
3. Gmail goes well with Thai.
4. Gmail blocks the spam before it gets to your inbox. Gmail helps make the spam filters more effectively and efficiently (than other free web-based email (Webmail) providers). If an unwanted message ever finds its way through, you can fight back by reporting it.

5. Of course, there are ads on Gmail, but unlike the other free webmail providers, the ads are not that intrusive.
6. E-mail Forwarding. You can forward your massage from your Gmail account to your other email addresses. 
7. Receive messages through email clients. Gmail offers you the Post Office Protocol (POP) and Internet Message Access Protocol (IMAP). So, messages sending to Gmail account can be accessed through email clients, like Microsoft Outlook, Windows Live Mail, Mozilla Thunderbird, or Lotus Notes.
8. Gmail provides you the Themes, which allow you to customize the look and feel of your Gmail account. Some themes, called “Dynamic themes”, will change automatically during the day depending on things like time of day or weather. Gmail will use the location information you provide to correctly time these changes with your local sunrise, sunset, and/or weather. You should also customize your location.

9. Send mail as: Use Gmail to send messages from your other Gmail’s email addresses.
Gmail's custom 'From:' feature lets you use Gmail to send messages from your other Gmail’s email addresses listed as the sender in place of your Gmail address. This feature makes it easier to manage multiple accounts from the Gmail interface.


10. Get mail from other accounts. Use Gmail to receive messages from your other Gmail accounts. Gmail’s Mail Fetcher can download messages from up to five other email accounts, centralizing all your email in Gmail.

11. Gmail is easy to use.
Gmail can read attached file as HTML.
Gmail can read attached document text, like MS word, through Google Docs.
Gmail can read attached presentation, like MS powerPoint, through Google Docs.
Gmail can read attached spreadsheet, like MS Excel, through Google Docs.



12. Gmail is good organizational features. It’s easy to group your contacts into one name.


Cons of Gmail:
Here are reasons why some people don’t like Gmail.
- Gmail doesn’t provide Reading Pane, Microsoft Outlook-like interface.
- Gmail can’t create folder to classify emails (like Yahoo! Mail can do), but, anyway, Gmail provides you the Labels.
- Gmail can’t sort the received emails, while Yahoo and Hotmail can do sort emails by sender, subject, date or size)
- There are some people who don’t like Gmail to group each message they sent with all the responses you received into one strand. They seem to enjoy the classic style of displaying emails based on the received date/time
- Gmail doesn’t
Here are “10 reasons to use Gmail” provided by Gmail by Google at https://gmail.google.com/mail/help/about.html
Gmail makes email easy and efficient. And maybe even fun.
 | 1. You don't like spam. Neither do we. Don't waste time with junk mail and unwanted messages. Gmail blocks spam before it gets to your inbox. If an unwanted message ever finds its way through, you can fight back by reporting it and help make our spam filters even better. |
 | 2. Search your mail instantly Use Google search within Gmail to find the exact message you want, no matter when it was sent or received. You don't have to spend time sorting your email, just search for a message when you need it and we'll find it for you. |
 | 3. Organize replies into conversations With Gmail, each message you send is grouped with all the responses you receive. This conversation view continues to grow as new replies arrive, so you can always see your messages in context. |
 | 4. Built-in chat: text, voice, or video With just one click, you can chat in Gmail with the people you already email or reply to emails by chat. You can even talk face to face with Gmail voice and video chat. All you need is a webcam and a small download that takes seconds to install. |
 | 5. Labels, filters, and stars...oh my! Gmail uses labels to help you organize with more flexibility. A conversation can have several labels, so you're not forced to choose one particular folder for messages. You can also create filters to automatically manage incoming mail. Starring messages is another way you can organize your inbox. Plus, it looks pretty. |
 | 6. Get your mail on the go The days of needing your computer to get to your inbox are long gone. You can now use Gmail on your mobile device to access your email from anywhere. |
 | 7. Lots of space (and counting) We're always working to increase the amount of free storage we offer in Gmail, and if you want even more, you can always purchase additional space. With all that space, you can archive instead of deleting messages, so they won't clutter your inbox but will remain searchable in case you ever need them again. |
 | 8. We have ads, but only the good kind With Gmail, you'll never see pop-ups or untargeted banner ads. Instead we display text ads and related links you might find useful and interesting. Learn more about how seriously we protect your privacy. |
 | 9. Save time Take advantage of Quick Contacts and Keyboard Shortcuts in Gmail to get through your email even faster. And don't forget that you can quickly find messages using Gmail's search feature powered by Google search technology. |
 | 10. All this is free? Yep. |
More information
E-mail client (or e-mail reader) is a front-end computer program used to manage e-mail.
Some e-mail client using nowadays are Microsoft Outlook, Mozilla's Thunderbird, and Apple Inc.'s Mail.
Webmail (or Web-based e-mail) is an e-mail service intended to be primarily accessed via a web browser. Very popular webmail providers are Gmail, Yahoo! Mail, Windows Live Hotmail and AOL.
Most improved free e-mail service | Gmail alternative; best features | Best free webmail service |