What solution can you come up with with mail?

Question

Mail server

The essence of the problem: the organization uses a free solution for Yandex Mail for the domain, and Outlook 2016 picks up mail via imap, the channel speed is 15Mbps (plus ip telephony) and letters come very badly (the mikrotik router is used and the Cisco l2 switch sb200 users are about 15) ; deploying your mailer is not an option!
Is it possible to somehow divide the traffic for everyone or increase the speed?

Answer 1

Kroilovo leads to the popadalovo.

Answer 2

you can go to pop