Sorry to sound boring, but get MailWasher.
This gives you the option to read and "bounce" an email without having to download it.
And if you then get your own domain name and use a unique email address for each email signup / website, etc. You know where the spam is coming from.
e.g I subscribe to
toastersareus@yourdomainname.com on the Toasters Are Us website; And
weknowwhereyoulive@yourdomainname.com on the We Know Where You Live webite. Later spam arrives addressed to
toastersareus@yourdomain.com
Simply and easy.
Roger...