Sent emails remain in Outbox


Outlook version
Outlook 2007
Email Account
Exchange Server
One of our users is experiencing a strange issue with his Outlook 2007 on Windows 7 (using Scalix not Exchange).

He has a program that sends out about 30 emails at a time using Outlook. i.e. The user clicks Send Invoices in external app, Outlook opens and you can see the emails fill up in the outbox.

However, even though the emails send they remain in the outbox.

I have seen similar issues before where emails hang in the outbox and don't send but that is not the case. The user can also delete or move the emails to another folder.

I have tried disabling anti-virus to see if that helps but it has no affect. The developers of the external app say they haven't heard of this problem before.

Any ideas how I can prevent them from getting left behind in the first place?


Outlook version
Outlook 2010 64 bit
Email Account
Exchange Server
Not familar with Scaliz per se, but could his PST file be corrupted or locked up.

Diane Poremsky

Senior Member
Outlook version
Outlook 2016 32 bit
Email Account
Office 365 Exchange
Try Safe mode and see if it helps. (Hold Ctrl as you click on the Outlook icon to start in Safe mode.)

Are you using POP or IMAP to scalix?

I'm positive there is a KB article about this type of issue but i can't find it. I don't recall if it had a resolution or just said "yeah, this happens sometimes." It may also only apply to exchange servers. I'll keep trying to find it.


Outlook version
Outlook 2010 32 bit
Email Account
Exchange Server
Setup :

Exchange 2010 Rollup 6

Outlook 2010 SP1 - Clean Install

Windows 7 SP1

Outlook - Multiple User Accounts added (3) - By Login not permissions on account

This is replicated on Four Machines for same mailbox

PA - Working from Home

Assistant - Within the Office

Office Pc


Message stay in outbox even though confirmed as deliverd .. Internally and Externally.

Done the Following :

Office Repair

OST Re-Created

Profile Re-Created

AV Disabled ..