We just migrated to Zoho and we are getting undeliverable errors with :
554 Error_Code 5.7.1 The message from ______ with subject _____ matches a profile the internet community may consider spam. Please revise message before sending.
Even revising the message will not work.
We found sometime using plain text to send the message worked but this is not going to be a permanent workaround for our business.
Our SPF records and domain keys are all set correctly.