How to configure Office 365, Microsoft Outlook Send As & Force Oultook update Global Address List (GAL)

Keywords: Office 365, Oultook Send As, Force Global Address List (GAL) update, This message could not be sent

1 Configure Send As permission in Microsoft Exchange

1.1 Login to Office 365 Exchange: https://outlook.office365.com/ecp

1.2 Click on “recipients” -> “mailboxes” or “shared”

1.3 Double click on one of the mailbox from the results list

1.4 Click on “mailbox delegation”

1.5 Scroll to “Send As” section

1.6 Click on “+” button, add user who should have Send As permission for the mailbox.

1.7 Click on “Save” button.

2 Send As from Outlook Online

2.1 Login to https://outlook.office365.com as the user we have specified in step 1.6

2.2 Click on your profile image at top right corner

2.3 Click on “Open another mailbox”

2.4 Enter the mailbox we give permission to from step 1.3 and click on “Open”

2.5 Now you can send email from this email address.

3 Send As from Microsoft Outlook Desktop Application

3.1 Launch Desktop Outlook

3.2 Click on “New Email” button

3.3 Click on “Options” from Menu then click on “From”

3.4 Click on From, if the address you want to send as appear underneath the “From” button, select it, if not, Click on “Other Email Address…”

3.5 Type the email address you have configured from step 1.3

3.6 Now you can send email from this email address.

4 How to resolve following Error

Note: You may encounter following error after step 3.6

This message could not be sent. You do not have the permission to send the message on behalf of the specified user.

This message could not be sent. You do not have the permission to send the message on behalf of the specified user.
(Microsoft Outlook - Send As)
This message could not be sent. You do not have the permission to send the message on behalf of the specified user.
(Microsoft Outlook – Send As)

To resolve this issue, try following method to Force Oultook update Global Address List (GAL) to resolved the issue.

4.1 Make sure the Desktop Outlook is closed

4.2 Open following path from Windows File Explorer

%userprofile%\AppData\Local\Microsoft\Outlook\Offline Address Books\

4.3 Cut everything within this folder

4.4 Create a new folder name it backup and open it

4.5 Paste to the backup folder

4.6 Try to launch Desktop Outlook and follow Section 3 again to Send As, this time there should be no error.

How to: Office 365 with Multi-factor authentication (MFA) for old Outlook Windows Manual Exchange Configuration

Old version of Microsoft Outlook does not work with Office 365 with MFA enabled, which will faill at sign in stage.

This Guide walk you through with proper configuration to make it work even for old vero of Outlook.

1 Logon to https://www.office.com

2 Open this link: https://portal.office.com/account/ (Or go to My account)

Office365.com -> Settings
Office365.com -> Settings

3 Click on Security & privacy -> Additional security verification -> Create and menagae app passwords

Office 365 -> My account -> Security & privacy
Office 365 -> My account -> Security & privacy

4 Create an App password, give it a proper name, copy the password save it for later use.

5 Open the Control Panel.

6 Type mail in search bar, click on search result

Control Panel -> Search bar
Control Panel -> Search bar

7 Click Email Accounts…

Mail Setup - Outlook
Mail Setup – Outlook

8 Click New…

Mail (Outlook) - Accout Settings
Mail (Outlook) – Accout Settings

9 Select Manual setup or additional server types, then click Next.

Mail (Outlook) -> Add Account
Mail (Outlook) -> Add Account

10 Select Microsoft Exchange Server or compatible service, then click Next.

Mail (Outlook) -> Add Account
Mail (Outlook) -> Add Account

11 Enter the following in the corresponding fields:

Server: outlook.office365.com

User Name: username

When finished, click More Settings

*Warning: Do not click the Check Name button at this step, or the configuration process will fail.

Mail (Outlook) -> Add Account
Mail (Outlook) -> Add Account

12 Click Security

Mail (Outlook) -> Microsoft Exchange
Mail (Outlook) -> Add Account

13 Uncheck Encrypt data between Microsoft Outlook and Microsoft Exchange.

Choose Anonymous Authentication from the Logon network security drop-down menu.

Mail (Outlook) -> Microsoft Exchange
Mail (Outlook) -> Microsoft Exchange

14 In the Connection tab, check Connect to Microsoft Exchange using HTTP, then click Exchange Proxy Settings…

Mail (Outlook) -> Microsoft Exchange
Mail (Outlook) -> Microsoft Exchange

15 In the Use this URL to connect to my proxy server for Exchange field, enter outlook.office365.com.

Mail (Outlook) -> Microsoft Exchange Proxy Settings
Mail (Outlook) -> Microsoft Exchange Proxy Settings

16 Check the Only connect to proxy servers that have this principal name on their certificate, then enter msstd:outlook.com in the associated text field.

Mail (Outlook) -> Microsoft Exchange Proxy Settings
Mail (Outlook) -> Microsoft Exchange Proxy Settings

17 Make following changes:

Check the On fast networks, connect using HTTP first then connect using TCP/IP box.

Select Basic Authentication from the Use this authentication when connecting to my proxy server for Exchange drop-down menu.

Mail (Outlook) -> Microsoft Exchange Proxy Settings
Mail (Outlook) -> Microsoft Exchange Proxy Settings

18 Click OK.

Mail (Outlook) -> Microsoft Exchange Proxy Settings
Mail (Outlook) -> Microsoft Exchange Proxy Settings

19 Click OK.

Mail (Outlook) -> Microsoft Exchange
Mail (Outlook) -> Microsoft Exchange

20 Click Check Name.

Mail (Outlook) -> Add Account
Mail (Outlook) -> Add Account

21 An authentication prompt will appear. Enter your [email protected] and password form step 4 in the corresponding fields, then click OK.

Windows Security - Login
Windows Security – Login

22 Click Next >.

23 Click Finish. Your account will be setup and you can open Outlook to begin using your Exchange account.

Mail (Outlook) -> Add Account
Mail (Outlook) -> Add Account