User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36

Steps to reproduce:

• add an gmail label which becomes an imap folder
• in TB enable "when getting new messages, always check this folder"
• add a gmail filter to direct certain messages to this folder ("Do this: Skip Inbox, Apply label ...)
• mail.notification.count.inbox_only=false to have the tray icon indicate new mail
• set the account mail check interval to 3 minutes
• get ready to send an email to this folder
• start TB
• immediately after the startup new mail check, send the email
• minimize TB to tray
• wait for new mail

Actual results:

• with IDLE, new email would be detected in under a minute
• but detection is ~ 3 min, the configured check interval

Expected results:

quick new mail detection via IDLE in under a minute

WFM at least for non-gmail.

I have 4 custom folders/labels in this gmail account, perhaps the count matters, but IDLE was definitely not working, new mail detection was multiple minutes late.

Imap IDLE (immediate notification) only works for Inbox and other folders that are in the imap SELECTed state. So unless you have recently opened one of the non-Inbox folders that you are filtering mail to, there is no certainty that that new mail will be detected in them immediately. If a folder is not in imap SELECTed state, new mail can only be detected on the timed interval when the folder right-click property is set to be checked for new mail.

Tb, by default, keeps Inbox imap SELECTed and 4 of the most recently open folders. So other than Inbox, you can't really configure a folder to always immediately notify new mail via imap IDLE.

So other than Inbox, you can't really configure a folder to always immediately notify new mail via imap IDLE.

If that's true, there should be a per folder setting to enable IDLE

(In reply to bughit from comment #4)

So other than Inbox, you can't really configure a folder to always immediately notify new mail via imap IDLE.

If that's true, there should be a per folder setting to enable IDLE

Yes, it's true and I agree. I've looked into doing that but it is not trivial to add. Also, not sure the current/actual meaning of "immediate notification" is documented anywhere.

(In reply to gene smith from comment #3)

Imap IDLE (immediate notification) only works for Inbox and other folders that are in the imap SELECTed state. So unless you have recently opened one of the non-Inbox folders that you are filtering mail to, there is no certainty that that new mail will be detected in them immediately. If a folder is not in imap SELECTed state, new mail can only be detected on the timed interval when the folder right-click property is set to be checked for new mail.

Tb, by default, keeps Inbox imap SELECTed and 4 of the most recently open folders. So other than Inbox, you can't really configure a folder to always immediately notify new mail via imap IDLE.