Mail server taking up main domain although it was not assigned to it

I have two servers with two separate IPv4 addresses, one is my mail server which I use with iRedMail while the other is the one I should be hosting my website on, on that domain I have two A records: one assigning "mail.mydomain.com" to the mail server's IP and the other assigning "mydomain.com" to my other server's IP but for some reason when pinging (or opening on a web browser) "mydomain.com" it shows my mail server, does anyone know the reason for this?