I have an Office 365 account and have set up two domains @a.com and @b.com. My user's primary email address is firstname.lastname@example.org however there are times I want to SEND FROM email@example.com from Outlook desktop application. How can I do this?
When you have a secondary SMTP address assigned to an Exchange mailbox, you can receive mail sent to that address but all replies will be from your default SMTP address.
You have two options: Create a send-only POP account or an IMAP account to send mail from that address or Remove the address from your mailbox and create a single-member distribution group (or distribution list) or shared mailbox for it.
Generally speaking, using a distribution group (DG) or shared mailbox is the recommended solution and is less messy than a second account downloading mail from your mailbox.
If you receive a lot of mail to the second address, a shared mailbox keeps the mail separate from the mail sent to your mailbox. Replies to messages in the shared mailbox will use the shared mailbox address but you’ll need to select the shared mailbox’s address to send new messages using it.
A distribution group will receive the messages and distribute the messages to your mailbox, instead of the messages being delivered directly to your mailbox. The only difference is that the To field will list the DG name, not your mailbox name. For both new messages and replies you’ll need to select the DG address as the From address.
To create a distribution group, you need to follow these steps:
- Remove second address from mailbox
- Create a DG and assign the address to the DG
- Make your user account the only member of the DG and give it send as permission
- When you want to send from the address, select the DG in the From field
If you are creating a new email address for the DG, log into the Exchange admin center skip to Step 2.
Step 1: Remove the address from mailbox
Log into the Exchange admin center and select recipients then mailboxes.
To remove second address from mailbox, select the mailbox name and click the Pencil icon (Edit), or double click on the mailbox name. Select email address from the list on the left, then select the email address you want to remove and click the minus icon. Click Save to save changes and close the dialog.
Step 2: Create the new distribution group
Next, you need to create a distribution group and assign the address to it. Still in the recipients section, select groups from the row above the mailboxes. Click on the plus sign and select Distribution group.
Create the new distribution group using the alias you removed earlier. Select the correct domain from the domain dropdown. Add group owners as members should be checked by default. If you are creating a DG for other users, their name should be in the Owners list.
Wait a few minutes for the Active Directory to update and replicate then double click to open the newly-created DG and continue with Step 3.
Step 3: Assign Send As permissions
Your user account is the only member of the DG and it needs Send As permission. You will probably want to allow outsiders to send to the DG address.
To make these changes, click the Pencil icon to open the DG for editing. If you want to allow anyone on the internet to send mail to this address, select delivery management and choose Senders inside and outside of my organization.
Select group delegation. Add your account (or the DG owner’s account) under Send As. Click Save to save the changes and close the dialog.
Step 4: Using the address to send email
When you want to send from the address, select the DG in the From field. The first time you use it, you’ll need to select From > Another Email address and select your DG name. It can take up to 24 hours for the Offline address book to update, but it will be listed under All Groups immediately.
After the first use, the address will be listed under the From menu.
You can create single member distribution groups in any version of Exchange server, however the screenshots and exact steps will vary in each version.