Before getting started: You must have the necessary permissions to send on behalf of a distribution list. If you do not have permission, please send a ticket to the IT HelpDesk.
Step 1: Navigate to webmail.isoc.org and login using your credentials.
Step 2: Compose a new message (or reply to a message sent to the Distribution List.)
Step 2: Compose a new message (or reply to a message sent to the Distribution List.)
Step 3: In the email composer window, click on Options and check 'Show From' from the display of options.
Step 4: Once the 'From' window appears, Click on the 'From' and select 'Other email addresses' 
Step 5: Type in the email address from which you wish to send.
Step 6: Compose your message and press 'Send'
Afterwards, in the webmail.isoc.org interface, you will be able to select the Distribution List address from the drop-down menu each time you would like to compose a message with that alias by following Step 3 'Show From' (above), then clicking the From drop-down arrow to select it from the list.
Step 6: Compose your message and press 'Send'
Afterwards, in the webmail.isoc.org interface, you will be able to select the Distribution List address from the drop-down menu each time you would like to compose a message with that alias by following Step 3 'Show From' (above), then clicking the From drop-down arrow to select it from the list.