Terrible Thunderbird v15.x IMAP Performance with AVG

My PC has recently been chugging a lot more than usual – massive disk activity and high CPU utilisation. Looking into it I quickly realised that it was happening whenever Thunderbird received a large bolus of new email – more than 15-20 emails within a minute or two. When I clicked on the folder with the new email, I could see in the status bar at the bottom that Thunderbird was very slowly downloading these new emails, while my disk and CPU went crazy.

Looking further I noticed that in Filemon, AVG was doing a lot of the work. Disabling AVG’s “Resident Shield” during one of these operations almost immediately fixes the symptoms – the email comes down much faster and the disk activity and CPU returns to normal.

This seemed to happen around the same time as Thunderbird v15.x was released, but I don’t want to declare that the culprit, especially as it is probably the same thing that I noticed with Microsoft Security Essentials that started happening around v11.x. I’m curious if something fundamental changed back then – either internally in Thunderbird, or perhaps within AVG – but it’s certainly possible that I’m just getting a little bit more email now and it’s just tripped my PC over the edge. I assume it has something to do with the way AVG hooks into the disk reading/writing operations – possibly Thunderbird changed something low-level there and it is simply reacting badly with how AVG does its real-time checking.

In any case, if you are experiencing massive slowdowns and system chunkiness using Thunderbird in conjunction with AVG, you can simply temporarily disable the real-time checking when getting a large number of emails. Obviously you probably don’t want to leave it off altogether.

Thunderbird Freezes When Deleting or Moving Email

I recently updated to the latest Thunderbird (v11.0) and was disappointed to discover that suddenly whenever I was deleting an email or moving it into a different folder, the entire application would freeze for 1-2 seconds while it processed that command.

I am fastidious about email and spend probably more time than I should ensuring everything is filed into appropriate folders (or deleted if I’m never going to look at it again). When you’re getting hundreds of emails a day, deleting and moving needs to be an operation that consumes near zero time, otherwise you’re suddenly spending way more time “doing email” than you should be. As a result, these freezes were massively irritating and caused no end of problems.

I reinstalled Thunderbird, which seemed to fix it temporarily – but before I knew it was happening again. I tried rebuilding and compacting folders – all for naught. I tried searching the Thunderbird Bugzilla looking for similar reports, but I couldn’t see anyone else having the problem.

I put up with this for a while trying various things, but eventually gave up and fired up the incredibly handy FileMon utility from the SysInternals guys to see if anything obvious was happening on the disk side of things that would account for this freeze.

Immediate pay dirt; this chunk of output in FileMon is shows the main part of what happened when I tried to move an email into a subfolder of the Inbox:

You can see there the operation started at 4:11:37pm and then the next activity was at 4:11:39pm – two seconds was roughly how long I was seeing Thunderbird freeze for.

Next step was looking at what MsMpEng.exe was – Microsoft Security Essentials. Turns out MSE was installed on my PC as part of a general system policy update at around the same time I upgraded to Thunderbird v11.0.

I tried changing the settings to see if that was indeed the cause – in MSE you just look for the Settings tab, select Real-time protection, and uncheck the ‘Turn on real-time protection’ box. Immediately Thunderbird started behaving normally with no more freezes.

Fortunately there’s an ‘Excluded processes’ option in Microsoft Security Essentials so you can add Thunderbird.exe to the list of processes to skip. This completely fixed the problem for me and now I’m back to moving and deleting emails fast as ever.

Thunderbird v3.x ‘Add to Address Book’ Adds to Wrong Address Book

I’ve spent a bunch of time in the last few weeks trying to create a unified contact list encompassing Thunderbird, Gmail and my Android phone. I had a minor irritation in Thunderbird when clicking ‘Add to Address Book’ (or starring a contact in the message view) would create the new contact in the ‘Collected Addresses’ address book, instead of where I wanted (the ‘Personal Address Book’).

Turns out where new contacts are added is dependent on an options setting – Options, Composition tab, Addressing sub-tab – you’ll see the below:

Change the ‘automatically add outgoing e-mail addresses to my…’ field to be whichever address book you want new contacts to be saved in. Note that this takes preference regardless of whether or not the checkbox for that option is selected.

Thunderbird ‘Write Error or Disk Full’ Dialog Error

Just had a bit of a weird problem with Thunderbird v3.0.3 throwing an error dialog with the following text:

An error occurred while sending mail. The mail server responded: qq write error or disk full (#4.3.0). Please check the message and try again.

Or in image form:

This of course looks like a server error, so I panicked and harassed our Ops guys, thinking the mail server was running out of space. Some simple testing indicated this wasn’t the problem – I was able to send through our mail server’s web interface (Zimbra) and others were able to receive mail with no problems, so it was clearly a problem at my end.

I restarted Thunderbird with no effect, and rebooted with no effect.

The solution was to right click my ‘Sent’ mail folder and hit ‘Rebuild Index’. I guess the index got corrupted somehow and it couldn’t write to the Sent mail folder, triggering that (wrong) error message.

Using Zimbra Calendars with Sunbird or Thunderbird/Lightning over CalDAV

We’ve just set up a Zimbra server as a trial in the office to use as a groupware solution – hopefully avoiding the Microsoft tax of Exchange.

First glance seems good, but it really highlights the deficiencies of the open source world in this area – Thunderbird/Lightning/Sunbird need a lot of work to catch up to Outlook/Exchange. Looks like they’re on the right track though.

Anyway, the first thing I tried to do was connect my Thunderbird/Lightning install with the Zimbra server. The documented method on the official wiki only included reference to connecting to your calendar via ICS using the webcal:// format.

Not really sure what it’s doing on the back end there, but I immediately ran into problems deleting events – a quick Google indicates many other users have the same problem. Fortunately in some other forum post (which I can’t find any more) I saw reference to Zimbra getting CalDAV support, which seems to work fine.

I’ve updated the wiki page above, but figure it’s worth saying again because it doesn’t appear to be widely known.

The CalDAV URL for your calendar is just:


It should possibly also be noted that you cannot map your Tasks in this way – ICS seems to be the only way to do that.

X Would Like To Recall The Message – But They Can’t

Ever got one of these? An email of the form “Person X would like to recall the message, [subject of the message goes here]”?

You’ll probably get something like this a few minutes after someone has just sent you an email you weren’t supposed to get. This happens semi-regularly – I’ll get a game press release that wasn’t supposed to be out in the wild yet, or someone has just sent a message to 300 people and put them all in the Cc: list instead of the Bcc: list… there’s a lot of great screw-ups I could refer to.

While this is, on the surface, just a hilarious artifact of newbs using computers, it actually is demonstrative of a pretty serious problem – controlling accidental information spread in an increasingly digital world.

A single mis-addressed email these days can bring down businesses and sway entire markets, and trying to control confidential information is something that companies are taking more and more seriously (but still probably not seriously enough to make a big difference).

Fortunately, open source has got you covered. Some clever students over at Carnegie Mellon University have created an extension for Thunderbird (the free, open source email client from the Mozilla team) that attempts to help control the spread of information by helping you make sure you’re sending emails to the right spot.

The extension, called Cut Once, learns who should be and shouldn’t be receiving emails that you’re sending (through some sort of document word count analysis). Once it has been trained, when you go to send an email it will check your recipients and advise you if there’s someone on there that perhaps shouldn’t be.

It will also suggest recipients that you might want to add – something which I feel would be less useful for my line of work, but possibly useful for others.