From the eQSL FAQ page:
Clever hams were sending electronic QSL cards by e-mail years ago. Back then, that was the only way to send them.
But e-mail is not a very easy way of exchanging cards. So, in 1998, we created the first eQSL exchange and called it www.QSLCard.com, and it has attracted a huge following. Our system does not use e-mail at all. So you really don’t “send” eQSLs. Instead, it stores your log in a large database. When another user uploads his log, we look at all the log entries that “match”, and allow you to display and print eQSLs from those matching log entries.
In April, 2000, we converted the entire system to a very robust and high tech database-oriented system and renamed our site www.eQSL.cc, the Electronic QSL Card Centre.
We are now the ONLY exchange for electronic QSL cards, with 56.0 million eQSLs from 302 countries currently online.
And, since virtually all of our technology is covered by patents pending, you can be assured that this will continue to be the place to maintain your online eQSL log!
So far I’ve received the following QSL cards through eQSL:
Some amateur radio operators will only use eQSL as a method to exchange QSL cards – other won’t use it at all. I will admit, it is a little unsatisfying receiving an eQSL as compared to receiving an actual QSL card in the mail.