Thunderbird and 1700 mail folders

[shacker23]

I have around 300 email users on a server which performs just fine - no complaints from anyone, except for one user who has 1,768 mail folders in his main account. He says that he is experiencing frequent timeouts while using Thunderbird, but that his iOS clients don't experience problems. He wants to know if there's some IMAP configuration change I can make that would make Thunderbird happier.

My position is that cPanel's default settings are highly optimized and tuned to service the widest array of possible mail clients. However, I thought I'd ask the experts here: Is there any possible or imaginable settings change I could make that would enable a better experience for this user (without negatively affecting everyone else)?

Thanks for any input,
Scot

 

[Infopro]

If it was me, I might send him here to see if there's anything helpful:
Performance - Thunderbird - MozillaZine Knowledge Base

 

[shacker23]

Thanks infopro, I'll do that.

Related: Would you consider it reasonable for a user to have that many folders? In other words, is this one of those areas where the user is using the system in a way it's not designed to handle? We enter territory here where the temptation is to tell the user "Don't do that / you're doing it wrong." Like a mechanic telling a car owner "Your clutch is wearing out quickly because you 'ride the clutch' - don't do that."

Or would you consider his usage pattern to be within the range of normal?

 

[Infopro]

I think I might also ask him to reevaluate his email storage choices.

I think we all have custom folders and rules set to 'if this then that', placing specific emails in specific folders. 1,700+ email folders for storage is excessive though, IMHO, I agree.

Was he doing fine, no slow downs when he was using only 1,743 folders, and it just started slowing on him when he hit 1,768?

 

[cPanelMichael]

Hello

It likely the user is reaching a limit configured for your mail server or for the application used to manage their email. While you could try reviewing /var/log/maillog to determine if a specific limit was reached, I would consider that to be an excessive amount of mail folders. The use of that many folders with IMAP is uncommon. You could try switching to Dovecot as your mail server if you have not done so already, as it's likely to handle the usage a little better than Courier.

Thank you.

 

[shacker23]

He has complained on and off of poor mail performance for quite a while (he is the only user complaining of this), but his complaints have gotten louder recently, as if he's hit some magic limit of what the communication between thunderbird and the server can handle in the polling intervals.

Switching to Dovecot is an interesting possibility. I hate to make changes that large just for the sake of one user, but WHM does make it look pretty easy. Is that change disruptive in general, or pretty transparent?

Thanks everyone,
Scot

 

[cPanelMichael]

The conversion is fairly straightforward. The amount of time it takes to finish depends on the number of email accounts on the system. As indicated in the interface, switching mail servers may cause some mail clients to redownload all stored mail messages for the account. This is primarily is seen with POP3 configured accounts.

Thank you.

 

[shacker23]

Yeah, I was thinking that might trigger a re-download. I do have quite a few POP users, and predict they would not be happy at all with that situation. I think I'll stick with Courier for now. Thanks.

 

[ckh]

If he has a lot of email in one folder, that can significantly slow things down also. Each email is a file. Big difference between retrieving a directory listing of 100 files and 20,000 files.

I think the most email I've seen in a directory totaled up to over 30 gigs. It was his own server and there were performance issues on the server. Clearing the emails he never checked fixed the problem.