Setting up IMAP Mail in Mail 3.6 on Power PC G4 Mac Mini - January 2020
I got bored using iCloud mail on my Windows PC and looked longingly behind me to the days when I used mail on my G4 computers. I tried to set up mail again but kept getting error messages. Then I remembered that I had had problems somewhere else because of Two-factor identification being activated on my iOS devices.
I was not able to change the settings in Mail 3.6 preferences so I removed the old account by going into Mail>Preferences clicking on the MobileMe account that was there and then clicking the - (minus) sign.
Because of the Two-factor identification I went into appleid.com and set up a password for “Mail on G4“. I wrote that down on a piece of paper - nearly as old-fashioned as my computer.
Then I went back into Mail>Preferences and this time clicked on the + (plus) sign. I filled in the fields and used the new password (after I found the piece of paper - just joking). I removed the tick from Automatically set up account and then clicked on Create
First I chose to set up an IMAP account from the drop down box which was originally showing MobileMe account. In the incoming mail server box I typed in imap.mail.me.com and in the outgoing mail server box I typed in smtp.mail.me.com
This worked for me after I had tried a number of other suggestions. I hope that someone else finds it useful so that we can keep those G4 machines going forever...