Read the forum guidelines
I'm using the Cox IMAP account settings on my Macbook Pro running OS X 10.8.4 and I have an iPhone5 setup the same. I receive email (incoming server - imap.cox.net) immediately on my iPhone5, but it takes several minutes upwards to an hour to receive the same email on my Macbook Pro. If I close the Mail app then open it, I get email. Or if I disable the Cox account in Mail and re-enable it I get email. Receiving email from OS X's Mail app while the app is open is slow.
OS X 10.8.4 Mail settings:Incoming Server: imap.cox.net - port 993 - SSL ONOutgoing Server: smtp.cox.net - port (Use default 25, 465, 587) - SSL ON Check mail every 5 minutes Connection Doctor within the OS X Mail app shows everything is working fine. No issues.
Same issue here reported on July 29, 2013.
In short, OSX email client is a joke. See this thread. I would suggest switching to Thunderbird.
My guess is when you open the client it creates up to 8 connections (Idle) and then syncs via the first one, and then every 5min the next one. So if 8 connections, 7x5min= up to 35min delay. But its kind of random or not documented which connection it polls to sync IMAP. Sometimes if its been long enough, it will start at session one, and it always starts at session 1 each time you open/close the client. The fix would be to disable Idle connections, but Apple (in their Ultimate Wisdom) has decided to disable that option. I think on the iOS version it detects what ever method the IMAP server uses, so even though there is no way to disable it, it working enough not to break it.
Wish there was a simpler or better answer, but thats what we gathered from that post you reference.
Thanks Trikein. I posted my question BEFORE reading through the forum where I found that other post from a month ago.
Because of the 7/29 post, I'm trying out Thunderbird which works fine and doesn't have the issue the OS X Mail app has.
I know I can keep the OS X Mail app open and eventually it will update the emails, but I'll give Thunderbird some time.
What I don't get is why this problem has been happening for so long and they haven't released a patch. Its only now showing up on this forum because Cox just started offering Imap, but it has effected other IMAP servers for a long time now. Apple can be so stubborn sometimes.
Yes, they can be stubborn and now with annual OS releases it will probably continue NOT getting the attention it needs.
We'll see if OS X Mavericks fixes it when it's released this fall. I'm not holding my breath since this issue is also in OS X Snow Leopard (10.6.8). I have Thunderbird on that Macbook Pro (13") besides my rMBP.