Zoho Mail extremely Slow Sending

Zoho Mail extremely Slow Sending

I have had a report from many users in my account that zoho webmail is extremely slow - so slow that a plain TEXT message is going out after SIX - yes that is 6 - minutes after hitting the button send.
That is not acceptable and I'd like to find out why
hopefully I get some answers here as I have not been able to talk to anyone in customer support - lines busy