right click the folder and select properties and then the repair button. It might just be a messed up index.

Thanks Matt but it hasn't fixed the problem. I ran the repair, restarted, but nothing is changed. Thunderbird thinks I have no mail since 24th August. I saw others reporting Thunderbird mail outages from 27th Aug, which is consistent with my problem, I wonder if there was an update or Apple update that changed something?

"checking inbox for new messages" seems to run an awfully long time (minutes), in fact it looks as if maybe it's hanging?

There are always folk reporting they can not get mail. Every time a new version is released, every time they get a dud update to their anti virus product, every time a mail provider changes the connection settings (only a percentage is recipients read the email from their provider suggesting change is coming.)

Thunderbird does not have outages, simply because it's entire existence in on Your Machine or mine or the machine of the person using it. Mail providers have outages, so if you were say using comcast and the forum was full of comcast customers with an issue starting from a date. Then there would be a clear issue.

In your case if you were using Windows I would point straight at anti virus.

Have you compacted the folder? It sounds like it may be corrupt in some way. AS compaction will often remove mail from a corrupt folder, I suggest you backup the folder before you compact.

Thanks Matt, I appreciate your comments, but. I am a Thunderbird user of 10+ years, working on El Capitan on my Macbook on Rackspace accounts. There was indeed a flurry of reported Thunderbird failures around 27th August. Thunderbird hasn't retrieved mail on this particular account since then. Thunderbird won't compact the folder, it hangs without completing. It's a bug, but I don't know what bug. Blaming the provider won't fix Thunderbird.

> goes through the motions of getting the mail, but nothing is downloaded.

Does "checking inbox for new messages" - in the status bar - what you mean by the going through the motions?

What exactly is shown in tools | activity manager and tools | error console when you do this?

And, who is your mail provider?

Hi Wayne, thanks for that and thanks for taking the time -

When I click Get Messages from the action bar in version 45.3.0:

Activity Manager reports "checking inbox for new messages"

Error Console reports:

Timestamp: 29/09/2016, 00:17:15 Error: An error occurred executing the cmd_getNewMessages command: [Exception... "Component returned failure code: 0x8055000a [nsIMsgIncomingServer.getNewMessages]" nsresult: "0x8055000a (<unknown>)" location: "JS frame :: chrome://messenger/content/mailWindowOverlay.js :: GetNewMsgs :: line 2723" data: no] Source File: chrome://global/content/globalOverlay.js Line: 103

searching on 0x8055000a and other bits yields these possibilities, in no particular order: - Inbox folder is busy - Norton - using menu to get messsages for *single* account works - creating a new profile helped (but don't know why)

WHO IS YOUR MAIL PROVIDER?

Mail provider is Rackspace.

Only 1 out of 4 accounts is failing to update, other 3 are fine, all Rackspace.

Using menu to get mail returns same error.

I did create a new profile, and followed the steps to switch to it, hasn't made any difference.

Norton? Is just a folk memory of years and years ago! I'm on Mac, no anti-virus stuff anywhere that I'm aware of.