<DKIM> MS Office365 'IMAP' server

Nicolas Sebrecht nicolas.s-dev at laposte.net
Thu Feb 19 12:56:20 GMT 2015

On Thu, Feb 19, 2015 at 11:33:33AM +0000, Richard Lewis wrote:
> Hi there,
> My organisation sold out to Microsoft for email and calendar services
> a year or so ago, making us all switch to Office365.
> I've been finding that I have problems connecting to the IMAP server
> it provides. It often takes several attempts to get a client to
> authenticate. Once it has authenticated, it will then normally stay
> connected for the rest of the day, although sometimes if left
> "unattended" (I'm not sure exactly what happens) it will drop the
> connection and I have to do the whole connection dance again. One odd
> feature is that the problem only seems to occur when I'm connected to
> my organisation's ethernet network; if I use their wifi (which is not
> simply a router stuck on the same network, it's a completely different
> network), or when I'm connected via any other ISP the problem doesn't
> occur.

I believe you're gointing to the right direction with your reseaches and
the imapsync thread.

I guess that when you're connecting from outside of the LAN, it's likely
less prone to hit the constraints due to a slower network.

> I switched to offlineimap a few months ago because I was getting
> frustrated with having to wait for my mail client to connect to this
> server. At least offlineimap is just in the background and I can still
> work with the Maildir even while it's busy failing to
> authenticate. Although it is still slightly annoying that it eventally
> gives up and the process dies, and then I have to start it again.
> However, I really would like to find a solution to this problem. I've
> tried asking my organisation's IT services department but they tend to
> ignore my tickets, I guess because they have no idea. I found some
> mention of throttling in the MS server
> <http://www.linux-france.org/prj/imapsync_list/msg01785.html> which
> could be relevant.

So, Miscrosoft add constraints to the IMAP protocol. Didn't know that...

> Does anyone have any suggestions how I could go about investigating
> this? Are there any settings in offlineimap that might give me more
> information about what's going on?

You're not the first to have glitches with Microsoft's products.

Some users set up a proxy IMAP server but I have no idea how it's
reliable in practice.

In an ideal world, we would support Microsoft products, might be like we
do for Gmail (having dedicated IMAP objects in the code). Sadly, nobody
in the team has such products in his hands and we currently had no one
contributing (with code) in this area. If you have programming skills,
you might be that guy.

Otherwise, you're either stuck with workarounds or picking up another
IMAP client, I'm afraid.

Nicolas Sebrecht

More information about the OfflineIMAP-project mailing list