I am posting this on behalf of my client who owns this account.

It appears that on the 7th of July a number of spam messages have been sent from the account without the owner's knowledge. 

It looks like Zoho have shutdown SMTP access for the account because of this. However, I strongly believe that the spam email has originated from Zoho itself and not from my client's machines.

If I try to re-enable SMTP access from the account's control panel then I get a message saying " Operation permitted for paid user(s) only." 

Exactly the same thing also happened to another of my clients on the same day. The spam emails are of a similar nature.

Please can you reinstate SMTP access to simon@intotodesign.co.uk with urgency please.

I would also note that my client has attempted to upgrade to a paid Zoho account only to have their credit card blocked because it appeared to be a fraudulent transaction. It seems dealing with Zoho is fraught with issues.