I have 2 yahoo IMAP accounts using the same server with a different discription name using Password authentication, different user names and passwords.
Also have 2 att.net accounts set up.
I don't see why the problem with gmail. Delete one SMTP server. Set up one account with the correct information and make sure you can get that one working. When that one is set up and working, try setting up one for the other user account.
Under SMTP account informaiton, Descritpion should be different from the other. Server Name: smtp.gmail.com
Under SMTP Advanced, use custom port 587, SSL checked, Authentication: Password, User Name: email password for that account, & Password: correct password.
Since both have different user names and passwords, they should be able to be created.
Unless: one is actually treated as an alias. When you log into the gmail site, do you have to log into each account to see them or can you see them from one login?