Some help with claws mail

Hi,
First of all I am still ignorant where it comes to Tor and networking so excuse me upfront for asking probably 101 questions but I have read the Tails documentation and more but to no alas so..

I use Tails or better yet, I want to use Tails as I feel,this is a great one-in-all package for private and anonymous webbing.

What I don't understand about setting up Claws mail is which ISP/email service to use. I mean, I thought about creating an anonymous emailaccount while in Tails but for some reason all the accounts I created I couldn't get them to work in Claws. I tried vmail.me, URSSMail, Gmail, mailoo.org, yandex....
I can create an account but I can't get it to work in Claws?!?

Then I read a few posts back in this forum one should just use the email given from the ISP as traffic inside Claws/Tails is tunneled anyway..?

Now I don't get this. I mean my mailaccount from my ISP or even Gmail is registered to my name and thus a weak link right? Regardless if the traffic is being tunneled. Wouldn't it be much more secure creating an anonymous mailaccount WHILE being anonymous in Tails? At least that's the way I see it.

So basically 2 questions: which scenario is more safe? Simply linking your personal day to day mailaccount to Claws from where all comms are 'anonymous' OR create a 'fake' account while being anonymous already in Tails?

Second question: If I'm right about setting up a fake (depersonalised) account being much more safe why can't I link those accounts to Claws? I want them IMAP-ed but I'm just not receiving any mail in Claws.

 

Despite all the help I managed to get Claws to work with another mailservice.
Appearantly all forementioned mailservices don't get along well with encrypted traffic or something since the settings I applied were all the same as before.