Email delivery delay

Email delivery delay

We're having a new domains where zoho is mail server, and we're experiencing very slow mail delivery (SMTP) > 2 min for at regular mail < 50 kb. And often 2-4 min for a mail ~1.5 mb. We're on a 1gb/1gb fiber.

Whats the problem, and how to solve, it's not acceptable.

//Hasse