Github user olegz commented on the issue:
https://github.com/apache/nifi/pull/827
@trixpan what notification? The exception is thrown by the SMTPServer's
thread without ever sending any type of ack about successful consumption of the
message so abrupt termination especially with message such as 'closed by
foreign host' simply means server is done and your message was not successfully
delivered.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---