salary in previous position

so i switched companies a couple of months ago. i had selected “no” to the question “mmay we contact your present employer”. now my new company sent me an email saying they need confirmation that i worked in the previous company. they require either T4s, letter of employment, or record of employment from my old employer. not that i haev anything to hide, but i thought companies aren’t legally allowed to inquire about your salary in previous positions, but each of these documents would contain that information.

I don’t think a letter of employment would have to contain your salary. Just call HR and ask for a letter that states "khanazam worked at xyz, inc. from x/x/xxxx to x/x/xxxx as a ".