Does anyone know if it's possible to host with Dreamhost, but leave DNS management elsewhere? I can't find any information on whether DHost's mail servers will link to a hosting account.
Haven't tried it personally, but I reckon you could probably add the domain via Panel then browse it's DNS via your domain list. Grab the MX info located within and add the records over at your management location.
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On top of what sXi said, you'll need the IP addresses for:mail.example.comwebmail.example.commailboxes.example.com
And be aware that should they move your mail to another server, you'll have to update those IP addresses again.