Upgrading Exchange

[Badaz52]

Hi everyone,

 

Over the summer I'd like to upgrade our Exchange 2013 box to Server 2016 and ideally to Exchange 2016 too. We use Exchange 2013 in hybrid O365 mode just for directory sync, we do not have any mailboxes on site anymore.

 

In the past I would install a new box, put the new version of exchange on and do a migration but I just wondered if the process is any different (or easier) now that we use O365?

 

How would you do it?

[3s-gtech]

You still can't in-place upgrade Exchange. Hey - it might work, but you won't find anywhere recommending it. I *think* that's the same for the hosting OS when it comes to an Exchange server. It's still a case of spinning up a new box, something that I'll have to look at sooner rather than later and not looking forward to it!

[chaplic]

If you have no mailboxes on premise you don't actually NEED to be in hybrid. Being by-the book you still need a Microsoft Exchange server but only to perform user administration!

 

So

Choice1: Maintain Hybrid - Stand up Exchange 2016 server, move autodiscover etc to it Rerun hybrid connector wizard. Sort out reverse proxying so it's pointing at 2016. Decom old excahgne

 

 

 

Choice 2: Remove Hybrid- Stand up Exchange 2016 server. Remove hybrid connection/ delete connectivity in o365. Point autodiscover at o365 directly. Probably establish a custom route between the two environments

 

Choice 3: Decommission Exchange on prem completely. Point your SMTP relay clients direct at o365 (if they are new enough). Occasionally get exotic with ADSIedit or powershell if you want to do things like create archive mailboxes.

 

 

I would go with 2 or 3, 2 is supported, but 3 if you don't have complex email routing on prem and don't mind a bit of getting hands dirty will save you lots of cost.

[Badaz52]

So I went with choice 1 and am having difficulties. We can send emails externally no trouble and we can email internally but externally received emails are sat in a queue with the following message:

 

[{LED=451 4,4.397 Error communicating with target host, 421 4.2.1 unable to connect socket connection refused, socket error code 10061 , we use a smart host so emails come to the internal exchange server first and then go back out to the smart host to send to the office 365 mailbox its this bit that isn't working. All DNS records are setup to point correctly to the right server and the FQDN of the new exchange box now matches the old one.

[chaplic]

Hybrid email between exchange and o365 cannot go through a smarthost, it must be a direct connection

Internet-> 3rd party gateway->internal exchange -> o365 should be the route