Primary SMTP change not applying in Exchange Online
Hi all, could really use some advice on a hybrid Exchange issue.
I’ve got a leaver mailbox for a user (let’s call her Alice Yamada). The current primary SMTP is:
alice.yamada-1@contoso.co.uk
It was originally alice.yamada@contoso.co.uk but the company adds a “-1” when a user leaves.
I’m now trying to change it back to:
alice.yamada@contoso.co.uk
The user’s AD account has been disabled and the mailbox converted to a shared mailbox, which the manager now has access to.
Users are still emailing the original address and getting NDRs, and the manager has requested the original email be restored so messages continue to come through.
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What I’ve done so far:
Checked that alice.yamada@contoso.co.uk isn’t in use anywhere (including soft-deleted objects) – all clear
Updated proxyAddresses Atrribute in on-prem AD:
SMTP:alice.yamada@contoso.co.uk (intended primary)
smtp:alice[.yamada-1@contoso.co.uk (kept as alias)
Waited over 48 hours for AAD Connect sync
Tried forcing a change by switching to a temp primary and back again
Confirmed AD is definitely correct
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What I’m seeing:
Exchange Online still shows alice.yamada-1@contoso.co.uk as primary
alice.yamada@contoso.co.uk is not present at all in EmailAddresses
PowerShell confirms the same
Also:
Can’t change anything in EXO (dirsync object)
Can’t add alias in EXO (blocked)
Don’t have permissions to create mail flow rules as a workaround
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So basically:
AD = correct
Exchange Online = outdated
Sync = not happening
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Question:
Has anyone seen AAD Connect refuse to sync proxyAddresses like this with no obvious error?
I don’t have direct access to the AAD Connect server, so I’m trying to rule out anything I might be missing on my side before escalating.
Any ideas or things worth checking would be appreciated.