IMAP access to Gmail incredibly slow, sometimes unusable
Hello,
We use G-Suite at work for Gmail service, amongst other Google services. As I have a range of mailboxes to use, and I like Thunderbird, I've decided to keep using it rather than the Gmail web UI. However I'm having frequent issues with IMAP access to Gmail revolving around performance. Specifically:
- P1: Messages take a long time to download for reading
- P2: Folder contents take a long time to download for listing
- P3: Slow acknowledgement of outgoing messages sending
- P4: Marking a message as read causes it to flick read>unread>read>unread>read
- P5: The above can easily cause the Thunderbird UI to become sluggish and occasionally freeze up entirely
- P6: Closing Thunderbird takes a very long time likely waiting for syncs to complete
I do not currently believe Thunderbird is at fault for this, particularly as the issue only impacts my work Gmail mailbox (other IMAP services are fine and near instant performance wise), and similar problems occur with Outlook 2016. Both Thunderbird and Outlook are incredibly mature applications, so I find it hard to believe that both have not undergone extensive tuning to stand the test of time.
I've raised the issue with G-Suite support however they insist that IMAP issues are a 3rd party problem and must be raised with the IMAP client application support. It also turns out that they deliberately clamp IMAP command rates on a per-user basis, regardless of whether you pay a premium for G-Suite or are a free Gmail user. (This has applied to my mailbox.)
It took a while, but the reasons I was informed of for clamped IMAP performance are:
- G1: Mails received size (The sum of all mails that arrived)
- G2: Total request size (The total volume of connection requests)
- G3: Total response size (The total volume of connection responses)
Point G1 regarding mail size I completely disagree with, particularly as we're paying for a premium to have G-Suite on a monthly per-user subscription. I'll be filing a complaint regarding quality of service to Google on that one.
Points G2 and G3 regarding volume of connection requests and responses, could there be any settings in Thunderbird (including via the advanced config editor) I can tweak to alleviate?
Steps I've already attempted:
- A1: Unsubscribed from "All Mail" folder: I removed this entirely via the Gmail settings so that IMAP clients never know it exists at all.
- A2: Reduce "Maximum number of server connections to cache" from the standard 5 to 2 or 1: This appears to make no difference, as the problem revolves around the number of IMAP commands being performed rather than the quantity of parallel connections.
- A3: Reduce the quantity of IMAP folders in which are synchronised for offline use: This is a double edged sword because folders not synced then incur a massively increased delay to read any messages within.
- A4: Synchronise only the most recent 6 months of messages, and limit to 512 kB.
- A5: Deleted my local MSF files for all folders for all of the above to refresh properly.
I'd be grateful if you have any further suggestions to make Gmail more usable in Thunderbird.
Thank you for reading, Adam
Modified by Wayne Mery
All Replies (7)
This article lists a number of factors that affect performance, some of them gmail-specific. To start, I would ensure that security/AV apps exclude the TB profile folder, Windows search is disabled, and TB global search is disabled or the index is rebuilt. Rebuilding IMAP folders, by deleting both the msf and mbox files, can make a big difference if the folder is corrupted.
Thanks for your response sfhowes. I'll check out that article. :)
I did try Thunderbird in safe mode already, and then again with add-ons disabled. For a while I ran with Lightning switched off as I suspected the busy work calendar could have an impact, but it made no noticeable difference.
Search is already disabled -- both barring Windows from searching mail, and the built-in SQLite searching facility. Its not often that I need to search my mail as I use organised folders (or labels rather) for this. I just use the quick filter bar when necessary.
Personally I don't believe that barring AV from scanning email storage is a good idea, or that it would severely impact performance. -- If real time protection was such a problem then every computer using it would be completely unusable every time it opened more than just a few files at a time.
I'm not seeing much of an issue with local resources. CPU, memory, and disk I/O are all relatively acceptable. Even with my large-ish business mailbox only approximately 512 MiB of private memory is allocated, on a workstation with 16 GiB.
Thunderbird does use a lot of CPU and memory on a regular basis when it closes down, but that'll be the exponguing inbox on exit feature. I don't have a problem with that.
The overall issue definitely appears to be specifically around how many IMAP commands Thunderbird issues to Gmail, as apparently this is too much. What I really need are tips to reduce Thunderbird's IMAP command volume.
You can read about the pros and cons of antivirus programs here:
http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Anti-virus_Software
Running in Windows safe mode with networking is a good test of the effect of AV on TB performance. It's not that every AV degrades performance, just the (many) ones that are incompatible with TB. Besides, no one is recommending the real-time background scan be disabled.
Many users have multiple gmail accounts configured without issues, but you could have problems if the time between checks for new mail is too short (keep at default 10 mins.)
Checking every 10 minutes does seem to be slightly better than the 5 minutes I had set, though there is still noticeable lag when browsing around. (Just not quite as bad.)
I don't think this setting can be pushed very far before becoming useless. If I get an urgent message it doesn't make much sense to not know about it for ~30 minutes.
Have you found more items to improve your speed?
See also https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues which goes more deeply into the AV subject.
No, the performance is as good as its going to get.
Intentional Gmail IMAP limitations are happening. To make the best of this you have to close down as many email client instances as you can to ensure none run in parallel, which includes any web UIs open, and Gmail mobile apps. (They all count.)
I've also been told to stop using Thunderbird's message filters, and instead use Gmail's own built-in ones, but as the built-in ones are pretty bad and cause overlapping I refuse to do this.
The lesson is not to use Gmail. Its just not good for very busy mailboxes. If you can afford to pay for G-Suite then you could also afford to pay for your own mail hosting and get a much better result at a lower cost.