If you have added one or more custom email addresses (See: Adding additional email accounts for multi-level support), you might be wondering which FROM address would be used when initiating a new ticket or replying to a user.
If you're replying to an existing ticket
The previously used email address will appear in the FROM field. For example, if user emailed you to email@example.com and their message has been converted to a ticket, replying to that ticket will put firstname.lastname@example.org to the email FROM field.
If you're starting a new ticket
The default email will appear in the FROM field. You can check what is your current default email by going to the Settings > TICKETS > Email page:
To select a different email address as default, click on the cog on the right and select "Make Default" from the menu.