Can't set up email.

I registered a domain with GoDaddy yesterday. I chose Zoho for Email hosting.

I followed every instruction I could find on setting it up. I verified my domain, which proved successful. I added some MX records (kept buggering that up, but think I got there in the end), and finally came to setting up my mobile (iPhone).

I haven't tried setting up my Mac yet (I'm getting a new one in a few days, so I'm waiting), but I can not get it setup on my phone.

I tried following this: https://www.zoho.com/mail/help/idevice-access.html, and the first time it seemed to work, before saying my password was incorrect. I re-entered it, and then tried all the others I use in case I'd set it wrong. When that didn't work, I deleted it and started again. I changed my Zoho password to the same one I used on GoDaddy so there'd be no confusion, but now, it says "Exchange account: Unable to verify account information". Multiple attempts, no luck.

Can someone please help me get this sorted? I need it up and running (and not doing anything funny) asap.

Thanks in advance.