How to connect to shared / additional mailbox via IMAP (Exchange 2010/2013)

I was solving the issue for one of our customers. They have application, which needs to log on to mailbox via IMAP, but administrator user doesn´t have mailbox. Here is the solution:

  • Administrator user “Anatolij.Stokurev” doesn´t have a mailbox
  • Anatolij.Stokurev needs to access mailbox “Shared.mailbox1”
  • Syntax to log on to additional / shared mailbox via IMAP is to use: DOMAIN\USERNAME\MAILBOXALIAS in username field and password in your application,
  • NOTE: get-credential command doesn´t accept syntax from point above (double in username) so you shoud enter credentials directly


  • I have created shared mailbox in Exchange 2013 and user in AD

shared creation1

I granted full access to user, who doesnt have mailbox Anatolij.Stokurev by command

Add-MailboxPermission Shared.Mailbox1 -user Anatolij.Stokurev -AccessRights FullAccess


Note: You cannot add permissions for user without mailbox in EAC / ECP. Powershell is the only option here.

Test via Telnet:

  • Prerequisite here is to have Plain text login set on Exchange servers (IMAP). Use the following commands to set plaintext login. IMAP services must be restarted before change takes effect.
Set-IMAPSettings -Server <SERVERNAME> -LoginType PlaintextLogin
Get-Service *ima* | Restart-Service
  • type the following command into the command line. I use Windows Server 2008 R2 and there is no Telnet client feature installed by default, so if you dont have it, please install it via Server manager MMC.
telnet <name of your imap server> imap (where imap is key word of protocol used by telnet client)
  • You will get OK answer from your setver if everything is OK
a1 LOGIN SALONOVI\Anatolij.Stokurev\Shared.Mailbox1 Minus30*  (According to IMAP protocol you have to insert valid username / password combination to logon to mailbox)
a2 LIST "" "*" (list folders from the mailbox)
a5 LOGOUT (End session)
  • Result is in the following Picture


Test via Outlook

  • Add IMAP connection to your existing profile or create new profile (File -> Account Settings -> New -> Manual Configuration -> POP/IMAP)
  • Open Settings
  • Change settings according the Picture:

outlook settings

  • Our admin user doesnt have e-mail address. Fill in e-mail address of the shared account instead
  • Into the username use the same syntax as before “DOMAIN\USER\MAILBOXALIAS”
  • In More settings TAB use working configuration of your SMTP server
  • Hit NEXT and you will get the test window. After test is OK you are ready touse new profile with IMAP connected to shared mailbox

4 thoughts on “How to connect to shared / additional mailbox via IMAP (Exchange 2010/2013)

  1. Pingback: How to connect to shared / additional mailbox via POP3 (Exchange 2010/2013) « exkb

  2. For Office 365 or Exchange Online, the username field format is: UserEmailAddress@domain\SharedMailbox@domain

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