This error message pops up in a scenario either when emails are sent in the same thread but using a different email account than the one used to send the initial email or it can be an error from our third party email service provider in case your email account was removed and reconnected at your end.

You would want to make sure that a reply/follow-up email should be sent with the same email account from which the 1st email was sent to the contact.

Did this answer your question?