Bulk email on CRM

Hi :)

i want to send Holiday greeting card using mailing list

the question is 

i understand there are some restriction on the email amount i can send in one batch 
is there a restriction on sending bulk emails directly from CRM ?
will the domain can be recognize as spammer or something like that ?
do i need to max bulk up to 100 emails or can i sent it to all my contacts in one batch ?

thanks,

Shani