Multiple email accounts (email channel) should be processed parallelly
Actual behavior:
Zammad is processing email accounts one by one which leads to the situation where adding one email account with a huge number of emails can block the processing of other email accounts
Steps to reproduce the behavior:
Add to Zammad account that contains 20k emails (account 1) - Zammad will start fetching those emails
Add to Zammad account that contains 3k emails (account 2) - Zammad will not fetch emails from account 2 until the processing of account 1 will be finished