720,341,564 people use Gmail all over the world.
The total people using Gmail are 425 million. This is because the popularity of Google. Gmail being a Google product is trusted by people.
They use Gmail, an email website to Gmail chat with their other friends who have gmail. They use IM programs. They use Facebook, myspace and Twitter to communicate with known and unknown people.
If one has a smart phone, which many people do these days, you can use your gmail account as an application on your phone. If you have an Iphone you can link your account to the email app on the phone.
yahoo
There are millions of people holding Gmail ID's. This is because mailing is an integral part of our life now. There are 425 million people that were using Gmail till 2012.
Gmail does not have an FTP server that is directly available for people to use. However, there are some people who claim to be able to hack the Gmail servers to get the FTP address but most of them are premium scammers.
Don't use the HTML view. Use the standard view
They are programs or people who deliver messages to other programs or people. They are Instant messaging programs. Ya can't use gmail with yahoo messager. Ya gotta use gmail with google talk.
Use Gmail notifier
I suggest you try gmail. I use it and it is easy to use for people!
Yes, you can use gmail on the iPad.
You can send e-mails or invites or attachments from GMail to any other e-mail address, not just GMail ones. However, to use google chat on your gmail account, the other person has to have a gmail account of the same type. For example, say one person has a regular gmail account, and the other has a school gmail account. Those two people wouldn't be able to use google chat together. However, if both have regular gmails or both have the same school gmails, then they could use google chat together.