Github user ijokarumawak commented on the issue:
https://github.com/apache/nifi/pull/1857
I've tested with [GreenMail](http://www.icegreen.com/greenmail/#examples)
server, which can be deployed with Docker or standalone Java app and NiFi Email
processors can talk with it seamlessly.
For POP3, if messages are not deleted, the same message can be fetched
again and again. So confirming whether it is deleted or not is easy.
For IMAP, there's some smart fetch mechanism is going on, so ConsumeIMAP
can not be fetch the same messages again, even if it remains in the mail server.
I used `telnet` command to confirm that messages are deleted (or remains)
based on the 'Delete Message' setting:
```
# Used different users
# Delete Message=True
$ telnet `docker-machine ip` 3143
Trying 192.168.99.100...
Connected to nifi-cp.local.
Escape character is '^]'.
? LOGIN [email protected] [email protected]
? STATUS INBOX (MESSAGES)
* STATUS "INBOX" (MESSAGES 1)
? STATUS INBOX (MESSAGES) // After consumed by NiFi
* STATUS "INBOX" (MESSAGES 0)
# Delete Message=False
$ telnet `docker-machine ip` 3143
Trying 192.168.99.100...
Connected to nifi-cp.local.
Escape character is '^]'.
? LOGIN [email protected] [email protected]
? STATUS INBOX (MESSAGES)
* STATUS "INBOX" (MESSAGES 1)
? STATUS INBOX (MESSAGES)
* STATUS "INBOX" (MESSAGES 1) // After consumed by NiFi
? OK STATUS completed.
```
Here is a NiFi flow template I used for testing available in
[Gist](https://gist.github.com/ijokarumawak/f898a4a38b3091ce59868584052e030c).
---
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.
---
