My emails aren't displaying in the sent folder at all. They are in the
"Outbox" folder,and this only happens when I send an email to more than 10
recipients.
Then you don't "have the same issue" as you said in your post. The original
poster said that the messages were moving from Outbox to Sent Items by the
recipients weren't getting them. When you post, please include an
_accurate_ description of your problem INCLUDING your Outlook version.
The first thing to do is to uninstall your antivirus program completely and
reinstall it without any email scanning features. You will still be just as
protected. Your AV program may be interfering. The next thing is to
increase your server timeout value on the Advanced tab of your account
properties. The next thing to try is starting Outlook in safe mode
(Start>Run, "outlook.exe /safe" in the Open field).