This turns out to be a mixed bag of things, partly due to data corruption and partly because I think there is a bug in the 'special' security evalution of mail.message in mail_message.py method check_access_rule.
After correcting the data corruption the error turns into an 'operation cannot be completed due to security restrictions', but only for one address.
In short, I think it's working in 99% of the cases now, except for one specific 'From' address which leads to the security error.
Marking as invalid as I can't provide the proper information for that 1%
This turns out to be a mixed bag of things, partly due to data corruption and partly because I think there is a bug in the 'special' security evalution of mail.message in mail_message.py method check_access_rule.
After correcting the data corruption the error turns into an 'operation cannot be completed due to security restrictions', but only for one address.
In short, I think it's working in 99% of the cases now, except for one specific 'From' address which leads to the security error.
Marking as invalid as I can't provide the proper information for that 1%