The pop and smtp address are the same? I've not seen that before.
Are you sure that is correct? I'd expect something like
pop.dhaka.net and smtp.dhaka.net
Actually, if I ping pop.dhaka.net or smtp.dhaka.net I get a response from
mail.dhaka.net responds as well on this ip address, so it seems smtp and pop are combined in one server .
What mail program do you use?