Is there a portable free email client with a login password?

Question

Email

Prompt the mail client under Win, with the password on an input. That is, so that without a password, access to the boxes could not be obtained even to read.
necessary features:
+ several mailboxes (like everyone should be able to do today)
+ portability and relative traceability (so that at least the texts of letters in clear text are not stored anywhere in the Appdata)
desirable features:
+ encryption of all locally stored content from mailboxes

Answer 1

good old thunderbird

Answer 2

https://www.essentialpim.com/ru/
xs about features in free version