You are more than welcome to register for a Moosend account using your Yahoo email address, but be advised that you will automatically be prohibited from sending any email marketing campaigns to any of your mailing lists.
The reason is simple: a Yahoo address is a personal email address and therefore your email campaign will most likely be considered as spam from the various filters used by email service providers, and will not be delivered properly. To this end we strongly urge you to register with us using a professional email address, preferably one that will easily be recognized by your recipients.
If you have already registered using your personal Yahoo address there's no reason to worry! You can easily add a new sender to your account using your professional email address. After you move ahead with the verification of the newly added sender you will be able to proceed with the dispatch of your first campaigns using the professional email address as the sender.