"Invalid UID Fetch attribute XSENDER"

[telwebb]

Hi - thought this may help some that haven't noticed it yet.

If the headers are moved by filters or whatever then they open without problem. So as a workaround you can create a temp folder as a sub of your main and set a filter to redirect incoming mail ("to IS ....) to that folder.

I know its not ideal but until T'bird resolve it (definitely their end) at least you wont lose mail

tel

[Soccypowa]

I did the marklark fiddle and it seemingly worked out for me to. It started working after first testing different connection security settings and then testing different authentication methods. Right before that the error message in de bottom left corner had changed behavior in my case, it had started flashing while earlier on when trying to preview a message it just popped up once. There is a thread on the Apple support forum regarding this as well, I'll report our "fix" to those guys. https://discussions.apple.com/thread/8034838

[telwebb]

cross fingers: as of this time, it appears to be working. Anyone else still having issues? I have a call with Apple Support tonight, and I will report findings.

Thought I had a workaround, but it's gone back to error now.

[mh_76]

cross fingers: as of this time, it appears to be working. Anyone else still having issues? I have a call with Apple Support tonight, and I will report findings.

Still having intermittent issues. It works for the few minutes after I do the fix but the error returns after a little while. I haven't tested to see how long the fix lasts but it's somewhere between a few minutes and a couple of hours. Thank you for working with Apple on this!

[fred9999]

cross fingers: as of this time, it appears to be working. Anyone else still having issues? I have a call with Apple Support tonight, and I will report findings.

Still having intermittent issues. It works for the few minutes after I do the fix but the error returns after a little while. I haven't tested to see how long the fix lasts but it's somewhere between a few minutes and a couple of hours. Thank you for working with Apple on this!

as it turns out, so am I. seemed to be working most of the afternoon, but just tried again, and it fails. All I'm doing is forwarding a short message from another account to my (unfiltered) inbox. I didn't find that filters made a difference, in fact, my filtered folders were the first place I noticed this issue. But for most of the afternoon, I was able to forward and read simple messages.

The guy on the Apple forum made an excellent point, and seems to coincide with what I'm seeing: something is running in background, and somehow eventually, the messages do get cached locally. Once they are, they are readable. I don't want to try the experiment that would confirm this, however (which I think would be the "repair folder" thing I tried before).

[hheckiii]

I'm with fred9999 (above) -- The issue is not occurring at the moment, i.e., Thunderbird seems to be working correctly right now. My theory is that Apple network wonks are busy building things out, and there was a configuration issue on the Apple side of things that introduced the "unexpected behavior" in Mozilla Thunderbird.

[fred9999]

All:

Apple Support is going to escalate the issue, we're taking screen shots as we speak. I've included this thread and the thread on Apple Support as reference material. Be patient, I think they're on the case ...

Thank you all for your variety of inputs, it was helpful in understanding the scope and nature of the problem!

[jfbourdeau]

Linux Mint
Thunderbird 52.2.1 64 bits

Same problem here....
Did find a workaround
JF
MTL Canada

[wlockman]

Invalid UID Fetch attribute XSENDER." when attempting to access email from the Apple iCloud email server using the SeaMonkey email client 2.48 on OS X Sierra but the same error occurs on Windows 10. This problem began for me on August 8, 2017. The only workarounds I've found are to use the Apple Mail client or iCloud mail at iCloud.com.

[omnichad]

Apple Support is going to escalate the issue, we're taking screen shots as we speak. I've included this thread and the thread on Apple Support as reference material. Be patient, I think they're on the case ...

There are some IMAP transcripts on the bug report. Apple Engineers may need to see it - https://bugzilla.mozilla.org/show_bug.cgi?id=1388461

It seems like one (or a few) misconfigured server(s) out of many. if you're unlucky enough to connect to one that advertises XSENDER capability, nothing works right.

[fred9999]

I didn't see the log in the bugzilla entry before, but no worries, I worked out how to log IMAP communications and sent a short snippet on to Apple. I don't know the protocol and don't want to spend too much time learning it, but suffice to say in the failing situation, the server reports a different capability string pre- and post- login. post-login in my failing example did indeed advertise XSENDER capability, which it later throws up on when the client requests a message body.

[hillmpcc]

Here is another piece of the puzzle.

I'm using Thunderbird 52.2.1 on a Mac running 10.10.5. If I reboot my computer before starting Thunderbird, then I can access my folders in my iCloud account... well some of them. Things like the Inbox, Sent, Trash and other folders that are in my iCloud account that I use fairly often.

I believe the distinction is that the folders I can access are ones that I use regularly so have accessed them recently.

If I don't reboot before restarting Thunderbird, I can't get access to my messages and just get the "Invalid UID Fetch attribute XSENDER" error.

I'm using IMAP to port 993 with security set to "SSL/TLS"

I tried the trick of changing the security between "SSL/TLS" and "STARTTLS" but it didn't work for me.

Maybe this will help figure this thing out.

[KenTenTen]

In the meantime, set an unconditional forwarding rule to some other account.
1. https://www.icloud.com/#mail
(login)
2. Click the gear at bottom left, choose Preferences in small popup
3. On General, select Forwarding, fill in your favorite, make sure checkmark is visible.

And another thing...

Running the web interface to icloud mail at the same time as Thunderbird seems to allow me to read new mail in Thunderbird. Nothing, or too much. (Sigh)

Following with interest.
Ken

[gene smith]

The reason for this problem is that the apple/icloud server is sometimes reporting XSENDER capability but then rejecting the XSENDER attribute in the UID FETCH request sent by thunderbird. This is explained in detail in bugzilla reports: https://bugzilla.mozilla.org/show_bug.cgi?id=1388461#c8 and https://bugzilla.mozilla.org/show_bug.cgi?id=1388461#c9

This seems to be somewhat of a randomly occurring problem. Sometimes no XSENDER capability is reported and this causes no problem. Other times the XSENDER capability is reported and UID FETCH (XSENDER ...) request succeeds. But sometimes XSENDER capability is reproted but UID FETCH (XSENDER ...) request fails which causes the problem.

This information needs to be communicated to Apple.

[fred9999]

All:

Problem has been escalated to Apple engineering. I was told by support not to expect an immediate response, but something on the order of a week. I will follow up with them if this is not fixed by then.

Those of you changing parameters or other things: I have been successful reading things previously unreadable by simply closing and reopening TB. If all it takes is connecting to a different server that may be configured correctly ...

Gene:

Thanks for pinning this down from the TB side. I sent them a trace that showed an instance of server reporting XSENDER capability but then rejecting it yesterday. I'll send them your response as a further highlight, as you're saying that they apparently have servers that do the XSENDER handshake correctly.