First account website loads when it shouldn't

[Galaxian]

I've noticed on both my VestaCP servers that the first account on the server appears on http requests where it ideally shouldn't, such as:

ftp.domain.com
mail.domain.com
etc

This, to me, is weird behaviour. Unfortunately, I'm quite the server admin novice, so is there something that I'm missing to prevent this from happening?

[Galaxian]

I would like to bump this because it's still relevant. Happens on an old, up-to-date VestaCP installation on Apache/Nginx, as well as a new on on Nginx only.

[ScIT]

For the "first account" problem: viewtopic.php?f=10&t=14070

But it is normal, that on ftp.domain.com a webpage will be displayed - this is the default webserver page.