How to combine several e-mails into 1 management system?

Question

Task Management

There are 6 Yandex boxes and 4 GMail
. There is no way to combine them - everyone is needed.
When replying to letters, it is required that the sender has an appropriate box.
It is desirable that it would be possible to configure the letter template separately for each mailbox.
Are there any email clients (desktop or web) that allow you to combine all this together and work comfortably.

Answer 1

outlook
outlook express
essentian PIM
and gmail itself