A few days, I was setup to zohomail and in the start, everything work fine, but some days later I can't recieve e-mails anymore, check the  Mail Delivery recieved:

Delivery to the following recipient has been delayed:

      ********************

Message will be retried for 2 more day(s)

Technical details of temporary failure:
The recipient server did not accept our requests to connect. Learn more at  https://support.google.com/mail/answer/7720
[(0) **** .com.br . [**.***.**.***]:25: socket error]