Multiple Exchange mailboxes in Outlook

[HCHTech]

There is another Outlook thread going where I again saw the warning against setting up multiple Exchange accounts in desktop Outlook. I've looked into this before, and I think this warning is a combination of hyperbole and protection against seldom-seen edge cases. Microsoft's own documentation says "by default the limit is 10 accounts", implying that you could go beyond that with some sort of settings change.

I have been doing this for years without issue starting with Outlook 2013, then Outlook 2016, 2019 & now Outlook365. I have two "main" email domains, one for commercial clients and one for residential clients. Both are Office365. I also have two separate notifications address I use for device notification messages, and two separate "support@" emails on the domains for a couple of my biggest clients. That is a total of 6 Exchange accounts on 4 separate domains all in the same Outlook profile.

When I first started hearing about the dangers of having multiple Exchange accounts, I tried setting up different profiles, but frankly, things get missed that way. I thought about just having everything forwarded to a single domain, but I need the ability to respond from the different addresses. I KNOW I'm also over the 50GB limit with all those accounts, even though I autoarchive everything older than 6 months.

Anyway, I've probably jinxed my setup now - but I just wanted to get it out there that this setup works just fine for me. I'm well backed up, but haven't seen any sort of corruption yet.

 

[YeOldeStonecat]

We've had a few clients where a user subscribed to several mailboxes. Even across several 365 tenants...as Outlook is not monogamous.

The other thread, IMO the issues in Outlook were due to how the shared mailboxes were manually added instead of the normal way of self populating when the end user was added as a member of the shared mailbox by the admin.

 

[Sky-Knight]

It can be confusing because only one is "the default", and with M365 licensing it helps if that's the mailbox with the license to authorize Outlook.

But beyond that? It's only a headache because profile corruption odds increase per mailbox and rebuilding the profile requires additional logins. Still, even in these cases it's easier to sort out than use of even a single IMAP mailbox.

However, I do NOT recommend doing this if you own everything. It's cheaper to have everything on the same tenant, and additional mailboxes are simply shared mailboxes bolted to the mailbox that needs them all. I have two domains on my tenant as well, and 6 different mailboxes that I monitor, but Outlook only has 1 account, and everything sets itself up for me in the event that something goes wrong.

So my reasons for avoiding this aren't technical, they're budgetary. I can pay for 1 mailbox, or 6. I'm going to pay for 1.

 

[nlinecomputers]

So my reasons for avoiding this aren't technical, they're budgetary. I can pay for 1 mailbox, or 6. I'm going to pay for 1.

Licenses are per human not per box, if you do it right. The only issue is archives you don’t get them on free shares.

 

[Sky-Knight]

Licenses are per human not per box, if you do it right. The only issue is archives you don’t get them on free shares.

I have Synology for that, but yes. And if you need extra space you can get Exchange Online licenses for those shared mailboxes cheaply enough.

 

[callthatgirl]

I haven't heard of any Outlook dangers regarding 10 exchange accounts. I've seen clients with 15 accounts, a beautiful mess of exchange/IMAP and POP. I literally laugh when I see this in the wild.

 

[Fred Claus]

I personally have three different Exchange email address on my Desktop Outlook with no problems.