How connect Outlook to Office 365 without change the MX record of my domain yet?

Question

I want connect my Outlook to Office 365 without change (yet) the MX record. On Outlook I've already an IMAP account to the current mail server and I want copy and paste only a few email manually. When all will work I'll change the MX record and I'll switch the current mail server off.

I've changed my record autodiscover.mydomain.com to autodiscover.outlook.com but unfortunately I can't authenticate on Office 365 because my default address (domain) at present is mydomain.onmicrosoft.com and not mydomain.com. I can't change default domain because I've not changed the MX record..

Solution

The answer to your question goes into two parts:

• Change the domain name: As far as I know, you can change the default domain name of your subscription without the need to add an MX record. so you may need to look again at your setup and insure that you have followed the steps to configure the domain correctly.

Step 1: https://support.office.com/en-au/article/Verify-your-domain-in-Office-365-6383f56d-3d09-4dcb-9b41-b5f5a5efd611?ui=en-US&rs=en-AU&ad=AU

Step 2: https://support.office.com/en-au/article/Change-your-default-domain-for-email-in-Office-365-1bd69e1c-9598-49ce-b341-9ac895dbe681

• Email migration: why are you doing it the hard way? since you're clients are running on IMAP, perform an IMAP migration, it take a bit of time to setup but it can't get easier than this, your users won't need to be reconfigured twice but only once, once they login into their new email they will have immediate access to their inbox.

IMAP Migration Steps: https://support.office.com/en-us/article/Migrate-your-IMAP-mailboxes-to-Office-365-3fe19996-29bc-4879-aab9-5a622b2f1481

Comments

[jlehtinen]

Change the username in Office365 to be [email protected], then use this username when setting up the account in Outlook. Should work fine.

[jlehtinen]

P.S. Microsoft support for Office365 is (surprisingly) excellent and opening a ticket with them would get you help with this very quickly.

[CSG]

Thanks for the answer. If I use [email protected] for the authentication when i'll change the MX record (and my default domain on Office365 ) all authentications will fail again and i'll have to reconfig quickly all clients manually. I don't want do this work twice!

[CSG]

now i' ll test your answer.

[CSG]

I can't use IMAP migration because this method have a limitation: a folder must have less than 500k items.. and i've to manage few users with a mail box over 20GB!!

[CSG]

i'm sorry but your solution does not work! selecting my ".com" domain does't appear the command "set as defaut". is it generated by the DNS errors?

[Noor Khaldi]

Your problem is different than the question title, I suggest you do more reading 1) you may for sure add a new domain name and verify it without the need to create an MX record: technet.microsoft.com/en-us/library/hh852557.aspx 2) I would highly suggest that you go through the Office 365 OnRamp tool: blogs.technet.com/b/msukucc/archive/2013/10/14/…