support needed

Hello,

I have migrated recently with my domain portal-dwapara.ro from a server to your server (zoho). So, my email is on your domain zoho. I need to modify my data on my account from where the domain portal-dwapara.ro is registered: http://www.rotld.ro/engleza/index_en.html

Here I need to introduce the "nameservers". The only option that I have is: mx.zoho.com and mx2.zoho.com.

Is this way of action Ok? Do I need to do something else also?

I noticed that when I send/receive emails my Mozilla Thunderbird needs a few seconds too long compared to the fasteness I was used to before, when my domain was not hosted by you. Could you explain why? Is it possible to fix this problem?

Looking forward for your support,

Thanks,
Eugen Niculescu