I got duplicated mail from K9 with Gmail, this started about a week ago, first there were 3 same mail received then 2 now, I am using Thunderbird on Desktop with the same email a/c without this problem, wonder if anyone has the same problem.

What precisely do you mean by "duplicated mail"?

Is K9 connected via IMAP or POP3?
Are other accounts set up in K9?
Have you tried reinstalling K9 and reconnecting it with your account?
Do you have any mail forwarding or rules set up?

I am using IMAP
I've 2 Google a/c in K9
I will reinstall to try again

I've no forwarding but filter set in Google, and that was set after the duplicated mail problem.


I read in the K9 forum others have the same problem, and found that it was the confusing folder display settings to caused that, I am very confused too, I don't know what is "all except 2nd class folder" sort of things, I thought it was like Thunderbird plain and simple.

K9 lets you specify for each folder (in folder settings) if it should be first class or second class. Think of it as priorities. That way you can specify other options by folder priority, like "Push mail from first class immediately and notify me, leave second class on the server till I pull it", that kind of thing.

IC thanks, that sounds strange to me that, this feature does not make too much of a sense to me than to auto empty trash on exit that not available on K9 mail !

It starts to make sense if you handle a lot of mail folders, then adjusting various options per folder becomes tedious.

The problem seems to have fixed after I disable IMAP and use POP on Google, K9 keep using IMAP coz POP does not work, it keeps saying my username/pwd not correct, now I keep both enabled on Google, it seems Google reset something after I did the above change and fixed my problem.

Update: sorry that didn't fix the problem I just receive double message

K9 uses IMAP. No other accounts in K9. Reinstall, and reconnect. Any mail forwarding or rules? Need more details. Thanks!

I use IMAP, no forwarding set, only have filter/label set on Gmail, reinstalled but still the same problem.


Thanks

I already post the question on the K9 forum but can get no answer so that I post in here, I use K9 on Android because I use Thunderbird on PC. I've been searching for Thunderbird on Android and I found K9, the developer said K9 is Thunderbird on Android so I give it a try, but they are actually miles away complete different things. One thing keep troubling me beside the duplicated mail received, is no auto empty trash feature, so that I've to delete the duplicated mail then empty the trash every time. I know this is free software I shouldn't expect too much, but before K9 I was using Aquamail, I paid for it, but it changed to subscription base so that I need to pay again to use and I don't want so I quit, and look for alternative.