If you are asking for new gmail account verification,I don't think it is necessary now a days we can skip the number verification system while creating new gmail so you can do unlimited skips as long you are creating new gmails.
no. these days gmail or any email like yahoo is now verry strict when it comes to signup process and they now requires their users to provide a valid cellphone number . You need to have a working simcard inserted on the phone in order to recieve the verification code via the sms or call and then you need to input that code on the sign up process in order to complete it.
Recently I created a new gmail through android application and it doesn't ask me mobile number for this purpose.So the terms of gmail maybe different from country to country I think.
If everything doesn't work you can go to the services section by clicking here. You're welcome.
Creating a lot of gmail is just like a spam, created in the same day with the same IP but if you are using a VPN for every email that you are created it might be different. And also, i think it really base on every country's rules, perhaps with the same IP's.