s1llyone

Q: Syncing mail between multiple computers

Up until El Capitan, I was able to sync my email between a laptop and multiple desktop iMacs by using a program called Chronosync. I have a mix of POP3 and IMAP email accounts. With the latest version of the OS, this syncing of the Mail folders has become broken. It used to be I could shut down email on my laptop, go home to my desktop, sync the ~user/Library/Mail folder between the laptop and desktop using Chronosync, and then start email on my desktop and be right where I left off in email on my laptop. Trying to do this now (OS 10.11.4 and Chronosync 4.6.6) results in a mess of empty folders and a long update process as Mail goes out and tries to sync/download email from my IMAP accounts - something that did not happen before.

 

I have been working with the good folks at Chronosync to come up with a solution but so far all attempts have been unsuccessful. Does anyone know how to keep a variety of POP and IMAP email accounts in sync between multiple machines running 10.11.4? Or, if this can't be done in Apple Mail, are there other email app options out there which will allow me to sync two email folders and be done with it?

 

Any help, suggestions, commiserations would be sincerely appreciated. Right now, I have email operating only on my laptop. I hate having all the eggs in one basket.

Posted on Apr 11, 2016 11:17 AM

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Q: Syncing mail between multiple computers

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  • by Glenn Leblanc,Apple recommended

    Glenn Leblanc Glenn Leblanc Apr 11, 2016 11:29 AM in response to s1llyone
    Level 6 (11,021 points)
    Mac OS X
    Apr 11, 2016 11:29 AM in response to s1llyone

    POP accounts are not designed for syncing between devices and is a pain to try doing that. Eventually, something will get corrupt trying to sync messages between devices.

    Are you sure you can't convert those POP accounts to IMAP? A simple solution for POP accounts is to use webmail for those accounts.

  • by s1llyone,

    s1llyone s1llyone Apr 11, 2016 1:27 PM in response to Glenn Leblanc
    Level 1 (4 points)
    Mac OS X
    Apr 11, 2016 1:27 PM in response to Glenn Leblanc

    Thanks for your response Glenn. Actually, using Chronosync, keeping POP account email in sync between computers is real simple and quick. I've been using a setup that has worked for many years UNTIL El Capitan came on the scene. There is something about how this iteration of the OS handles Mail that has broken this method. I know IMAP accounts handle email differently from POP but again, in the past with CS, it has been a solution that has worked. Now, however, when I attempt to do a sync, Mail wants to go out and re-sync all the IMAP email again - even though it resides locally after the sync. Most disconcerting.

     

    Re converting POP to IMAP. If anything, I would want to go the other way at this point in time. POP sync works but IMAP seems broken - at least in Apple Mail. I want to use Apple Mail to access both POP and IMAP. Using another method, like Webmail, just further complicates things.

     

    No where, in anything I have found/read, is there a description of exactly how this sync got broken with this OS version. But it is broken.

  • by BobTheFisherman,Apple recommended

    BobTheFisherman BobTheFisherman Apr 11, 2016 1:32 PM in response to s1llyone
    Level 6 (15,483 points)
    Apr 11, 2016 1:32 PM in response to s1llyone

    IMAP is not broken. Use IMAP to sync email accounts across multiple devices. IMAP is designed to do exactly that. POP is not designed for syncing email across devices. If anything, using some third party app to try to force POP to do something it is not designed to do is complicating things.

  • by Glenn Leblanc,

    Glenn Leblanc Glenn Leblanc Apr 11, 2016 2:42 PM in response to s1llyone
    Level 6 (11,021 points)
    Mac OS X
    Apr 11, 2016 2:42 PM in response to s1llyone

    As Bob says, IMAP works fine in Mail. Some people have problems with certain providers, but most work just fine. If you want to list your POP account providers, maybe someone here can give you some insight to whether or not it works well in the Mail application.

     

    I didn't say it was not possible to sync POP like you are doing. I said at some point it would probably cause corruption and problems with what you are doing. I don't know what OS you were using before, but Mail works about the same for several OS back. A few things changed like the storage folder changed from V2 to the V3 folder from Yosemite to El Capitan. Structure remains about the same.

     

    I would suspect that Chronosync may need updating. I've never used it or know what it does exactly, but you may want to check with them. If you have to choose the folders to sync, I suggest you verify the path to the mail location. As I said, the major change is that mail was moved from the V2 folder to the V3 folder. This might be as simple as you making the adjustments there in Chronosync.

    The correct path to mail is ~/Library/Mail/V3.

  • by s1llyone,

    s1llyone s1llyone Apr 11, 2016 4:36 PM in response to Glenn Leblanc
    Level 1 (4 points)
    Mac OS X
    Apr 11, 2016 4:36 PM in response to Glenn Leblanc

    Bob and Glenn - thanks for your feedback. I guess I'm not doing a very good job explaining myself. Syncing POP **and IMAP** email accounts between machines has never been a problem for me when using Chronosync up until ElCap. I have been doing this successfully almost everyday for 8+ years. I am using both the most current version of the OS (10.11.4) and Chronosync (4.6.6). I know about the new V3 folder - goodness knows I've spent enough time looking at its contents and all the other places Mail makes an appearance in the filesystem.

     

    Before EC, this is what I could do.

     

    1. Quit out of Apple Mail on my laptop.

    2. Start CS on my desktop which would then connect to ChronoAgent on my laptop.

    3. CS would go through my Mail folders and basically get the two Mail folders (on laptop and desktop) in sync with one another.

    4. Start Mail on my desktop and basically be where I left off in Mail on my laptop after shutting it down in #1 - both POP/IMAP worked!! I swear to God things worked. ;-)

     

    So, prior to EC, I could basically copy the Mail folder from one computer to another and things worked - both for POP and IMAP accounts. When I try to do the same thing now, it does not work. There must be Mail files hidden elsewhere now (and I am not talking about account settings stuff - I am not a newbie!) that are not being backed up when moving from one machine to another. The guys at Chronosync (whose business is syncing files between computers) are stymied by this change in Mail as much as I am. The one beta solution they offered me did not work.

     

    So I put it to you both - assuming accuracy of copying and placement of all files - do you think copying the user/Library/Mail folder from one computer to another and then starting Mail up on second computer (that has had Mail working on it beforehand) should work? Seems to me it should - POP accounts which have had emails downloaded to local computer and erased off server should all be there and IMAP would go out and do its natural syncing which should not take long because the pointers in Mail as to the state of last IMAP sync would be up to date. Does this sound rational? To me it does because it worked this way before. But not now - at least for me.

     

    How do other people, using Apple Mail and a variety of POP and IMAP email accounts - keep their mail in sync between different computers. My setup (desktop at home and laptop at work) can't be all that rare or special.

     

    Any other insights?

  • by Glenn Leblanc,Apple recommended

    Glenn Leblanc Glenn Leblanc Apr 11, 2016 5:22 PM in response to s1llyone
    Level 6 (11,021 points)
    Mac OS X
    Apr 11, 2016 5:22 PM in response to s1llyone

    Do I think it should work. Probably yes, but I have no way to test it with POP accounts and I only have one computer. Make sure both computers are running the same OS.

     

    Is this a good idea? No. You run the risk of file corruption doing this. And syncing corrupt files from one computer to the other will then transfer the corruption to it also. Glad it worked out for that long. Computer OS keeps changing and if you can get it to work today, will it work tomorrow or after the next upgrade. Mail is pulling other info out of the database and it may be getting corrupted. You might try re-indexing Mail on one computer then try syncing to the other.

    Nothing has changed as far as folder structure except for the V3 location. The mail file format are still the same and no other files are changed in the MailData folder. Restoring the V3 folder from one computer to the other should work the same.

     

    You never really said exactly what was the outcome of trying to sync. Is Mail working OK other than sync.

    What you should do is verify on both computers that Mail is functioning OK as separate devices. If not, then fix the issues on whichever one is not right. If one computer is having corruption problems with Mail, then it might affect the syncing issue.

    On the chance that there are no issues with the computers, then it's up to Chronosync to make a version compatible with El Capitan. Did they say it was? If they offered a beta version for you to test, then maybe they know there is a problem.

    If you want to test it manually, then manually transfer the contents of the V3 folder from one computer to the other. Then open Mail on the other computer and see if it works. That should tell you if it's a Chronosync problem or not.

     

    Most people who want to sync their mail between devices use IMAP, or just set the computer to leave the message on the server when using POP so other devices to download. I think what you are doing as far as trying to do an exact sync is very rare. People have discovered IMAP which does exactly what you are trying to do. So why bother with Chronosync when IMAP will do that immediately with no extra steps. Of course I understand that if your provider doesn't offer IMAP, then that's a different story.

    And if you ever throw a phone into the mix, then Chronosync will probably not do you any good.

  • by s1llyone,

    s1llyone s1llyone Apr 11, 2016 6:19 PM in response to Glenn Leblanc
    Level 1 (4 points)
    Mac OS X
    Apr 11, 2016 6:19 PM in response to Glenn Leblanc

    Thanks Glenn for taking the time (and making the effort) to respond. I think at this point in time I will investigate moving to all IMAP. Wish I did not have to make the change but sometimes you have few choices. Thanks for letting me vent a little. Cheers!

  • by Glenn Leblanc,

    Glenn Leblanc Glenn Leblanc Apr 11, 2016 8:16 PM in response to s1llyone
    Level 6 (11,021 points)
    Mac OS X
    Apr 11, 2016 8:16 PM in response to s1llyone

    I think overall it would be the best decision and easiest way overall.

     

    If you do more testing with this or find the problem, post back the results. As I said, it probably should work if Mail is not having other problems, and a manual test should verify that.

    It really isn't a question of whether or not replacing the files will work, as I know it will from backups of the same drive. It's moving the files between different computers that provides the doubt on consistency, especially when doing that over and over.

     

    Good Luck

  • by ChicagoT,

    ChicagoT ChicagoT May 8, 2016 8:44 AM in response to s1llyone
    Level 1 (4 points)
    May 8, 2016 8:44 AM in response to s1llyone

    While II haven't tried this with Apple Mail - I use it to keep my documents / desktop / music / downloads in sync between multiple laptops...

     

    Have you tried a combo of symbolic links and Dropbox for this? Set a symbolic link for your Apple Mail directory to Dropbox (or Box, etc.) on each of your machines. Let Dropbox or Box do the work of keeping everything in sync for you. My guess would be as discussed earlier the risk of corruption if you have multiple devices open simultaneously writing to this folder, but you seem pretty disciplined about this with CS. Dropbox would notify you of a "conflicted copy" but that might be pretty ugly with Mail. It works fantastic for the other folders above just haven't tried it with Apple Mail.

  • by PETER TIMOTHY COX,

    PETER TIMOTHY COX PETER TIMOTHY COX Sep 27, 2016 11:44 AM in response to ChicagoT
    Level 1 (4 points)
    Sep 27, 2016 11:44 AM in response to ChicagoT

    The origin of the broken email synching between machines in El Capitan (and Sierra) is that Apple Mail cleverly started building a deep hierarchy of folders within ~/Library/Mail/, where the email is stored, and at one level a common folder name is defined as a long hex string that is likely based on the hardware address of the Mac one is running on. Therefore any conventional attempts (e.g. using Dropbox, or an app like ChronoSync) to sync between two Macs break because this hex string is different on the two Macs. It is a pain in the neck but I presume the Mail author(s) decided this change was critical for some arcane reason. Maybe its critical for icloud usage or something. Personally I just gave up on Apple Mail because of this. (Both Airmail and Postbox, for example, remain more conventional in their file naming and conventional synching is possible between machines, although they store emails in database files which can be pretty large and they're the objects which have to get synched.)