Migrating exchange, sharepoint and skype to Office 365 (Hybrid)

No if you want your mail to continue to be routed to your on-prem exchange server, then no don't change the MX record. Leave it pointing your inbound exchange or firewall or whatever you have it pointing to currently. once it hits your exchange, your exchange will know where the mailbox is and route it to O365 if that is where the mailbox resides.

so do i just have to only update the CNAME record and the TXT record? My txt looks different. it looked like this
 v=spf1 +a +mx +ip4:69.90.162.250~all
I updated it to :  v=spf1 +a +mx +ip4:69.90.162.250 include:spf.protection.outlook.com ~all
but i am still unable to perform any test migration.
please help

there is a few things you need to do
1. AADConnect
2. hybrid configuration wizard
3. do migration endpoint created?


these text record and MX record probably the least problem compare to the above

Now i have migrated two users into office 365, but the problem is that they are isolated from the network and now users randomly complain they cant receive external emails. Please helpp!!!

what do you mean isolated from the network. give details of issue.

so I migrated two users from my on premise network to office 365. both users smtp were updated to .ca from .local. Note that i have the remaining users on .local. i noticed both users cant send emails to other users in the domain. the email messages dont deliver. i only updated the .TXT  and CNAME records on my dns. my MX records still points to my exchange on prem not office 365.

First don't ever just migrate users, you should always use test accounts to make sure everything is working the way it should.
I would suggest migrating them back to your on-prem environment.

When you setup your hybrid and ran the hybrid configuration wizard, it would have created a send connector on-prem (on-prem to 365) so that on-prem users can email o365 users, and it would have created a connector in O365 (o365 to on-prem) so that your O365 users can email your on-prem users.

If these connectors wasn't created you may have setup the hybrid with minimal configurations when you should have used full configurations.
You can either re-run wizard and select full config or you can manually create the connectors, see below link for help.

https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/use-connectors-to-configure-mail-flow/use-connectors-to-configure-mail-flow

I set it up with Full configuration. Not minimal. Is is a requirement to have a routable AD domain? for my ad server?

Yes that is required when moving mailboxes from on-prem to O365, but not required when sending emails from O365 to on-prem, but yes you do have to have a routable email domain.

I have a  certificate on my exchange server. it was not listed as a requirement., i thought idfix resolved that?