This is a known problem. I have been complaining about this issue since Apple released iOS 4.0. It was in that release that their mail client started using a new protocol called CONDSTORE, and the dreamhost IMAP servers have a bug in their implementation of CONDSTORE. CONDSTORE is a feature which is supposed to make it a lot faster to synchronize your email between devices.
After dreamhost blew me off repeatedly I went to Apple to ask them to explain what the issue was. I sent them all my email logs and they explained it in GREAT detail to me, so much so that I was able to search the internet for a bug in the dovecot imap server condstore implementation, and sure enough I found that such a bug existed and that it had been fixed.
I explained all this to Dreamhost during November and December of 2012, and they wrote back to me and thanked me profusely, and also said that the fix I pointed them to has been confirmed and verified.
Since then I have sent them emails routinely asking them when they plan to deploy this fix but all I ever get back is "Top minds are working on it" (you get the idea).
So it's utterly a joke that this 4+ year old bug, which has had a solution KNOWN to dreamhost for 2 years, is still impacting the increasingly HUGE number of people that use iOS and Dreamhost.
And meanwhile, Apple has ported the IMAP CONDSTORE implementation to Mac OS X as well, so things get out of sync on your main computer as well.
And the reason this doesn't happen with your gmail account (in case you're wondering): gmail servers do not implement CONDSTORE.
Which implies, of course, that Dreamhost could have easily fixed this problem by using the SAME VERSION of their current server with just the CONDSTORE implementation disabled. Even that appears to be too much for them.
I am commenting on this thread today because I have been searching the internet for good alternative to dreamhost. I've reached my limit.
Just in case you don't believe me, here's the more important email from dreamhost during my exchange with them:
- After reading this response, please consider visiting
- the survey below to comment on its quality. Thanks!
- If the service you received from us was exceptional, please consider
- tweeting your love for @dreamhost. It'll warm our hearts, soothe
- our souls, and get you good karma at some point down the road.
Thanks again for all the info you sent our way, Jonathan. This is
completely confirmed and verified, and we have an upgrade to the latest
version of dovecot planned for the near future. This should indefinitely
fix the compatibility issues with the older version of iOS. I do not have
an exact ETA for you at this time I'm afraid. Until then, moving a
mislabeled file to trash, as well as moving between other folders other
than trash, is a workaround. I apologize for the inconvenience, but this
should eventually be cleared for good once we have dovecot tested and
upgraded across our mail network. If we can perhaps help with setting
your domains up on an external mail service, or with anything else
unrelated at the moment, please reply here and let me know. I do hope we
can keep you around!
Thanks for your patience and understanding,
Sean H (communicated with you before on twitter)