@scott After upgrading to Mavericks, I noticed a new folder was created: "Macintosh HD/Incompatible Software".
In my case, Avast and Flip4Mac were there. OSX should prevent these software from opening but Avast was still running. Please read "OS X: About the incompatible software folder".
So, please check if there is any incompatible software on your computer and try to remove it.
I'm having IMAP syncing problems too.
Having it my new MBP, iMac, and MacBook Air.
Originally, I was not having the issue on my MacBook Air (probably because it is an old system that has been upgraded). However, in doing some testing, I removed my IMAP account, and added it again, and now the issue is also on my MacBook Air.
Additionally, I added the mail accounts both ways (in Internet Accounts so it propogates on all Macs, and seperately within the Mail application). Both methods result in the same issue.
Looks like it's Thunderbird for me (and mail on my iPad/iPhone)
I am having the same problem with a non-Google imap account. Since installing Mavericks, I cannot access it on my MBP. It is available on my iPad, and probably on my iMac with Mountain Lion. Either it tells me that the password is incorrect, or the SSL port cant be accessed. Very odd. How long will it take Apple to straighten this out?
Same problem here. iPhones/iPads appear to be working fine. Emails come *in* to Apple Mail, but if I delete them on my iPhone, they stay on Apple Mail. Tried restarting, doesn't help. Disappointing, I don't remember so many concurrent 'show-stopper' problems since I switched to Mac back in 1999. Photo Streams are a mess (on Apple TV), Mail issues, FaceTime pretty much doesn't work since iOS7, tsk. I can't make the argument right now for my friends and family to switch.
It's as if Apple checks to see if it works on one device, then voila! It's considered done.
Guess I'll do the Apple feedback route and see if anyone cares anymore. :^(
I have filed a formal bug with apple on this issue, via: http://bugreport.apple.com/
Bug number is listed as: 15516430
And has been logged as Rank 2, Important.
And Apple has since marked it as: Duplicate of 15440215 (Open)
So someone else has also formally logged the issue and its status is currently 'Open'. I'm hoping that this means someone at Apple is working on it and a solution will turn up in the next udate...?
As and whe I get an update from Apple I will update this discussion.
I too am having this issue, my MBPro will not sync my large work IMAP account any longer. My iMac at work (mac server managing email accounts) works fine,
The MBPro works fine at the office- but not if on a different network.
Reset DHCP, changed SMTP folders, etc.
Works fine on all three iOS devices.
I really don't want to tempt fate (I also opened another topic on the same subject as here), however for some strange reason (which I have no idea why), the problem has simply gone away !!!
I have not changed my IMAP mail settings at all. There has been no OS updates recently either.
So I'm totally lost as to why it has mirculously started to sync properly again.
I was having problems with my inbox not showing the same as gmail in the browser, tried deleting the email account in mail and adding again.. and still not working.
So I tried playing with the label settings in gmail, I turned on [Imap]/Archive to show in IMAP and show if unread. I then restarted mail to see the gmail folder with Archive showing. I then went back to gmail and unchecked the [Imap]/Archive box again and clicked hide. After restarting mail again it now seems to be working and has started syncing the inbox properly again.
Tell you what worked for me - Postbox was on sale Friday for $6.99. Installed it, configured it, life is back to normal. Actually a little better, as so far Postbox seems to have a little more customization to it, but not to the point of just being absurd. I've been using Apple Mail since it's inception, but enough is enough.
I just wanted to add my voice to those here. After sleeping, my Mail.app doesn't sync propoerly either until stopped and restarted. Nothing to do with anti virus (don't have any) and nothing to do with GMail (don't have any either). Just plain old not-synching. My IOS devices are fine, even my other macs, but my new iMac 27 late 2013 with 16GB just refuses to sync. I'm writing this as it rebuilds the mailbox, to see if this is any use....