Hello,

Im using Windows 7 and Office 2013 on both my laptop and desktopIn Outlook 2013 (using outlook.com account IMAP) when I move a e-mail from my inbox or sent folders to one of my personal folders or the deleted folder the recipients are duplicatedThis only happens on the machine that I use to move the e-mailIf I check the mail on the other machine everything looks normal.

Please try to create a new Outlook profile and test the issue still persists.

And, you may connect your outlook.com account through Exchange ActiveSync Protocal, that would provide you another solution for managing your Memail messages, calendar, and contacts better within Outlook 2013.

(File > Info > Account settings > Add > Manual setup or additional server types > outlook.com or Exchange ActiveSync compatible service > Mail server is "m.hotmail.com")

Thanks.

Tony Chen
TechNet Community Support