I am running vagrant. In it, I have Ubuntu 14.04 server and installed postfix.
I am able to send email using
sendmail firstname.lastname@example.org (after typing in body etc.)
How is postfix able to send email to gmail even though I configured nothing about postfix (did not specify any smtp settings for my gmail accoun, for example)
Also, postfix looks like a full-fledged email server? What can I install so that I can send email without having to install postfix (and without giving any smtp settings for this program X)?