[BUG] Direct Reply: Email Intercepter doesn't wake up

Description:

After setting up Direct Reply a new IMAP instance is started successfully, and first emails are fetched, but after a while (about 30 minutes) the E-Mail Intercepter stops fetching new emails.

Server Setup Information:

• Version of Rocket.Chat Server: 0.61.0
• Operating System: Linux Ubuntu 16.04 LTS
• Deployment Method(snap/docker/tar/etc): self build bundle
• Number of Running Instances: 1
• DB Replicaset Oplog: yes
• Node Version: 8.9.4

Steps to Reproduce:

1. set up Direct Reply with IMAP
2. create some direct emails and then wait for a longer time before answering
3. E-Mail Intercepter doesn't fetch new emails

Expected behavior:

E-Mail Intercepter must fetch new emails

Actual behavior:

E-Mail Intercepter stops fetching emails after a while, no logs.

Relevant logs:

working logs:

Feb  1 15:01:48 testrocket testrocket[1057]: Starting Email Intercepter...
Feb  1 15:01:48 testrocket testrocket[1057]: Starting new IMAP instance......
Feb  1 15:01:48 testrocket testrocket[1057]: [connection] Connected to host
.....
Feb  1 15:01:49 testrocket testrocket[1057]: => 'IDLE IDLE'
Feb  1 15:01:49 testrocket testrocket[1057]: <= '+ idling'
Feb  1 15:01:49 testrocket testrocket[1057]: => DONE

stop fetching:

Feb  1 01:05:59 testrocket testrocket[1057]: => DONE
Feb  1 01:08:42 testrocket testrocket[1057]: => DONE
Feb  1 01:08:42 testrocket testrocket[1057]: => DONE
Feb  1 01:10:20 testrocket testrocket[1057]: => DONE
Feb  1 01:10:20 testrocket testrocket[1057]: => DONE
Feb  1 01:12:08 testrocket testrocket[1057]: => DONE
Feb  1 01:12:08 testrocket testrocket[1057]: => DONE
Feb  1 01:17:08 testrocket testrocket[1057]: => DONE
Feb  1 01:22:08 testrocket testrocket[1057]: => DONE
stop fetching
Feb  1 15:01:49 testrocket testrocket[1057]: => DONE
Feb  1 15:06:49 testrocket testrocket[1057]: => DONE
Feb  1 15:10:05 testrocket testrocket[1057]: => DONE
Feb  1 15:10:05 testrocket testrocket[1057]: => DONE
Feb  1 15:15:05 testrocket testrocket[1057]: => DONE
Feb  1 15:20:05 testrocket testrocket[1057]: => DONE
Feb  1 15:25:05 testrocket testrocket[1057]: => DONE
Feb  1 15:30:05 testrocket testrocket[1057]: => DONE
Feb  1 15:35:05 testrocket testrocket[1057]: => DONE
stop fetching

Start with the Direct Reply email interceptor and its IMAP IDLE handling, reproducing the setup and waiting beyond the reported 30-minute interval. Use the provided working and failing DONE logs to trace why fetching stops; done means new emails continue to be fetched after the interceptor has been idle.