The Jira Service Desk 4.2.1 mail handler in Project Settings > Email requests doesnt load requests

[Макс Быков]

Community license. MailHandler stops handling mail after getting some number of messages. Is there any limitations?  Log  in application tab keeps silence and register neither success nor fail. Logs in folder dont keep any errors.  All other messages in inbox stop handling and have state unread in inbox. If set the last read message in state "unread" - mail handler sets its state in "read" in inbox, but dont show succes or fail.  As a rule the last message has attachments. Any thoughts?

[Макс Быков]

I see the message have processed after all but it takes about an hour for 4M message how to monitor the proccess of fetching messages to understand the possible reason of slow fetching? Is there any possibility to make several threads of fetching?