mail constantly goes offline

Same problem here on my Retina MBP. So sick of this, I've been scouring the internet for weeks trying to find an answer. Im stumped. IMAP, 3 accounts, El Capitan latest, IMAP goes offline, SMTP usually will connect. All works fine on my iPhone or using icloud.com.

PLEASE GOD SOMEONE HELP US!!

I suspect it isn't the wireless chipset, although I'm certainly not ruling it out. It will run OK after a restart for me for an indeterminate amount of time (only because I haven't noticed a pattern). Also, my iOS devices work just fine. It was one of the very frustrating things about this problem that mail I had received and deleted on my Mac was still showing on my phone because Mail on the Mac would sync once with the IMAP servers, but when I went to delete things it would have lost the connection to them.

Again, I hope Sierra corrects this.

I have two thoughts:

1. Am I the only one who leaves Mail up in its own desktop, and swipes back and forth to others? Can't tell if that makes a difference, but just a thought.

2. I use MailButler because I like that it populates images into peoples' cards from the web. Makes it so much easier to tell who's writing to me at a glance. Anyways, anyone else using that? I'm wondering if it's contributing to my issue.

I use mail on its own desktop, my boss does not. We both have the issue.

No MailButler here.

Ok, thanks. Wanted to make sure it wasn't my flow.

You made the Time Warner observation. I'm on TWC for internet at home, as well. I don't think I have the problem as much when I'm elsewhere. I wonder if there's anything to that?

I think that is the best avenue to explore here. As i've had multiple people in the same place have this problem without having it elsewhere I wondered what we all have in common.

First was Gmail accounts - but then I added a hotmail account and that is affected as well, as are icloud users here. Next would be that we all connect to the same wifi and have the same ISP. We never have the problem at the same time so I can't believe it's a router fault causing an immediate effect. My boss has TWC at home and doesn't have the problem there.

I don't necessarily believe it's a specific ISP but possibly hardware they use, or a way some kind of wiring works or other...

Not sure if you're still having this issue, or anyone else for that matter, but I have a thought:

Have you tried going to the menu bar: Mail>Add Account>Other, then enter your iCloud address and password.

Otherwise, my instinct is that the "p12-imap.mail.me.com" portion of the server seems weird. I don't recall ever seeing that. Anyone agree?

Glad to see that this topic has become pretty active once again. Perhaps the resurgence of posts will catch the eyes of someone at Apple...

I think there are some good troubleshooting ideas above. To address the question about ISP: I'm in Canada on Rogers experiencing this issue, so it seems less likely that it is an ISP issue. Also, when I got my brand new MBP Retina a couple weeks ago, I fresh installed El Capitan and did not download any third party apps whatsoever, and I was still experiencing the issue, so I don't think MailButler or anything like that is the culprit.

I was so frustrated with this and figured I have nothing to lose that I enrolled in the Apple beta for Sierra and installed it two nights ago. So far I have not had any Mail disconnects or iTunes timeouts. That said, the last time I thought I had fixed this with an NVRAM reset, I went a few days without any issues before Mail and iTunes starting acting up again. I'll report back if the issues return or in two weeks (whichever comes first) if there are no signs of the bug in Sierra.

Glad, as well, to see someone keeping this post alive!

Sierra Public Beta presented no issues with Mail that I had experienced prior. I've since gone back to 10.11.6, and only the occasionally "server bump" that will come and go before I have time to troubleshoot.

Would love to hear more as time goes on from you!

Thanks,

Michael

What has really thrown me with this is how intermittent it is. I can try a solution and not have any disconnects for a week, sometimes a month or two, leading me to believe that I've fixed it. It always comes back. Like I said earlier it magically went away on my own MBP from July '15 until about a week or two ago, while persisting with my boss and other coworkers.

I wouldn't think its the .me server causing issues as this seems to affect any email provider account.

Likewise, the problem is very intermittent with me also-- yet I have no problem with iTunes.

And like many of you, I'm also using an Airport Express/Extreme to connect to a modem via Time Warner.

I've restarted my computer a couple days ago and I haven't had any IMAP Mail issues yet.

Let's hope it gets cleared up soon!

Thanks for everyone's feedback!!! 🙂

For what it's worth, I don't believe I've had many iTunes issues, and certainly not to the extent as my Mail issues. To be clear, are you guys talking about Apple Music or iTunes? I use Apple Music most every day and rarely have connectivity problems.

My iTunes and now Apple Music have been working just fine. Only mail issues for any of us.

To clarify, yes, this thread is concerned with the mysterious and seemingly random Mail disconnect issue. I only mentioned the iTunes timeout issue (this thread on MacRumors explains it well) in one of my earlier posts because whenever I am experiencing a lot of Mail disconnects, I also experience the mysterious and seemingly random timeout error from iTunes, even when I'm not actively doing anything in iTunes. I thought (and still kind of do think) that the two are related in some way, and that the iTunes timeout message might also be caused by whatever connectivity/hardware/software issue that the Mail issue is caused by since they seem to happen in conjunction (at least on my machine).

For the sake of staying on topic, though, I think the Mail issue is the priority in this thread.

Just to chime in on the multiple theories I've seen.

I'm in Alaska so I suspect I'm using a different ISP than everyone else here, which lowers, but does not eliminate, the chance of it being an ISP related issue.

I do not use Mail in a separate desktop space, and I don't use any third party add-ins.

I am not having any problems with iTunes on my MacBook Air, the computer on which my mail accounts "live". I will admit that I rarely use iTunes here. Very occasionally I find that iTunes goes deaf on my iMac, which acts as the server for my AppleTV with movies and music. I will very rarely have to restart the iMac to restore that functionality, but I haven't seen any relationship to my Mail activity on the Air. I had pretty severe problems with it a while back, but that was a problem that was finally solved completely with El Capitan, so I don't see a relationship.

As of today I haven't had the problem since I last restarted a couple of days ago, but that really is no indicator.