Hashcat help with email combining to password.

[Snoopy]

So I need to get the data base of the email by using breaches so I can get the passwordhash and then I can get the password?

more or less yes

but it would be very very very unlikely to get a database dump from any of the great email providers

most* breaches are old websites, forums and little shops, then you could get email:pwhash, crack the hash and try wether the password is also used to login into the email itself (most humans are lazy and use their passwords more than once) or not

*of cource there where some really big breaches too