So i have done some research and found that you can use command line switches to open different profiles in Outlook.

e.g. "C:\Program Files\Microsoft Office\Office15\OUTLOOK.EXE" /profiles "ProfileName"

What i want to do is open two different profiles at the same time. So i already have one profile open, i use the method above, however it simply opens a copy of the profile i already have open rather than the one i defined in the command line switch?

I know it works because if i don't have a profile open it opens the profile i specify. Is this by design? If so what is the point in having a profile switch? If someone could help me get this working it would be great.

Thanks in advance.

Hey Joner,

here some good link for you about command's 

http://www.outlook-tips.net/how-to/using-outlook-command-lines/

Thanks for your reply. im guessing that...

"Notes:

Before using a command line switch, you need to close Outlook and verify it's closed in Task Manager's Processes tab."

...means that what i am trying to achieve isn't possible :(

The reason i want this is that we have a user who administrates a lot of other users mailboxes. She was having performance problems with Outlook due to the .ost for her profile being 16GB! I have since removed a lot and compacted but it is still at 9GB. My idea was to split the mailboxes she manages so half could be on one profile and half on another. Rather than having to close and reopen Outlook every time she wants to open a the other profile it would be good to have them both open so she can monitor all mailboxes. Doesn't look like this is possible though....

No, you cannot open different profiles at the same time.  Have your user add all all mailboxes that she wants access to in her main profile.  I'm assuming she has Outlook 2010 or greater, which is the first version that supports having more than one Exchange mailbox.

Hi Eric,

Thanks for confirming this. We already have all the mailboxes that she wants on her main profile. The problem is that Outlook cant handle processing all of these at the same time and continuously crashes and hangs. As i said previously the .ost for her profile was 16GB, i have managed to reduce to 9GB but Microsoft themselves say that anything above 5GB needs extra hardware power for a good user experience.

http://support.microsoft.com/kb/2695805/en-gb 

• Up to 5 gigabytes (GB): This file size should provide a good user experience on most hardware.
• Between 5 and 10 GB: This file size is typically hardware dependent. Therefore, if you have a fast hard disk and lots of RAM, your experience will be better. However, slower hard disk drives, such as drives that are typically found on portable computers or early-generation solid-state drives (SSDs), experience some application pauses when the drives respond. 
• More than 10 GB: When the .ost file reaches this size, short pauses begin to occur on most hardware.
• Very large (25 GB or larger): An .ost file of this size increases the frequency of short pauses, especially while you are downloading new email messages. However, you can use Send/Receive groups to manually sync your mail. For more information about Send/Receive groups, see the "Are you synchronizing many RSS feeds?" section.

I find it surprising that you cant have multiple profiles with different mailboxes when you consider you can only have an .ost up 5GB to have a good user experience. Maybe this is something the developers can put into the next version of Outlook? Or release as a patch?