Tips for an email marketing service accepts my emails ?

Hi guys

I used to use mailchimp as email marketing with emails I catched with their own forms. But I have 5000 emails that a catch with another method. And I want to put them in mailchimp ? The problem is they don't accept emails from elsewhere

So how can we do ? Is there another service I can use ?

Please tell me guys !
Thank you

you can use email service providers like amazonses and mailgun