Outlook cannot establish an encrypted connection to 365. "An encrypted connection to your mail server is not available"
On the surface this appears a common issue with many suggestions regard autodiscover online. However let me explain my REAL issue:
I am creating a new mail profile - via control panel, mail, profiles. (an existing profile already exists)
Latest version of office/outlook 2016/365
I can create a new profile to connect to a 365 account on a different tenant.
I can create a profile to connect to a local exchange server.
If I try to connect to problem tenant - I get the encryped error as above.
So I jump on my laptop, and get the same issue.
I remote into a different client and I can connect OK - but it is a different version of outlook. So I guess that may be the issue - although I CAN connect to other 365 tenants.
I remote into a different client that uses the same outlook version - and same problem.
I create a new USER profile on the PC (it is domain connected so basically I logged in as a different user) - and if I allow outlook to configure the account with its startup login wizard - and it connects perfectly to the problem 365 tenant.
FYI - the exchange connectivity analyser online suggests there are no problems.
I have tried connecting via firstname.lastname@example.org and also email@example.com exactly the same issue and scenarios.
I am going in circles -
is it my PC?
my outlook version?
the tenant in question?
My current guess is it doesnt like being a second profile - although this poses a problem as the reason for setup is for a mail migration to 365 - every user (40 of them) has a current profile and we need to setup a second profile connected to 365 ready for switchover.
I dont think this is becuase we still have the old domain pointing to the old mail host.
Basically - old domain - pointing to old host,, new domainname pointing to 365, after migration the old domain will be pointed to the 365, but the new domain will be the company default. So I cant see a reason for this to be related.
The 365 tenant isnt new and has been used for dynamics for a few years, and only recently had exchange/365 added to it.
The outlook support and recover tool only madee things worse my trashing any currently existing, working profile.
My only other solution/workaround would be to create a connection to 365 with the first profile, then create a new profile to connect to the old mail server - but this will require resynching email for both accounts and this client has limited bandwidth and several mailboxes over 10gb each - which is why I wanted to commence synching the new 365 profiles in batches and at night before cutover.
Any new. lateral thinking suggestions are welcome.