I assume you mean e-mail addresses. I don't believe there is a central registry where you can get accurate data. There are surely billions, if not more. There are many people - especially poor people - who don't use internet at all; but on the other hand, many people have several e-mail addresses, for different reasons. Spammers create lots of fake (or one-time-use only) addresses; perhaps millions a day - so the question is, do you want to include those in your count. But even if you count only email addresses that are still active, there are probably several billions.
There is no way to accurately tell how many emails have been sent but it is in the quadrillions
There is no legal limit to emails.
5 emails
you can send at least 100
Unknown
5
Appproximately about 75 - 125 depends how big the emails are reallly
Jeff receives around 1200+ emails a day and he trys to answer as many as possible.
Impossible to answer ! Emails are never the same length, and the header is different every time !
25
According to recent studies there is over 294 Billion emails sent per day. Only 1.9 Billion of the 294 Billion emails were from actual people.
HTML format exists for emails to allow one to see the contents of web pages in emails. Many emails are now web based mail programs such as Yahoo and MSN so they are more suited to HTML format.
You go to your sent items in you email account thing ank at how many you have sent. Then you count each email you sent to the person. Then you will know how many emails you sent to that person. Repeat this method to find out how many emails you sent to other people.