• At the prompt enter the password - same one you use to access the webmail account.
• select the checkbox 'Use Password Manager to remember this password'
• click on OK

Q: Do you see the checkbox 'Use Password Manager to remember this password' or is it missing?

Toad-Hall - Thank you for your reply. Somewhere along the line I had found the 'save' box' having previously looked everywhere else for it! The following actions were taken before seeing Toad-Hall's reply: I deleted the smtp password entry hoping that both would be put back together. [Read something somewhere in the support website]. No such luck. At the next start of Thunderbird I entered the password and ticked the 'save' box. Only the smtp password has been saved in the saved passwords list. The pop3 password is still missing from the list. A further opening of Thunderbird required entry of the pop3 password again.

Definately odd as you would have thought if there was a problem saving then the smtp would not have been saved.

So this makes you wonder if the smtp was not really deleted in the first place. It just appeared to be gone, but the files were not updated.

It seems that the password only works within the session.

Please check this:

• 'Menu icon' > 'Options' > 'Options' > 'Advanced' > 'General' tab
• click on 'Config editor' button

It will say to be careful :)

• In top search type: password
• look for this line: mail.password_protect_local_cache

Is the Value 'False' or 'True' ?

• If it says 'true', double click on that line to toggle to 'false'
• Close window - top right X
• click on OK

• Exit Thunderbird
• Restart and enter pop password at prompt and select checkbox to remember password
• click on OK

Then check:

• Menu icon > Options > Options > Security > Passwords
• click on 'Saved Passwords'
• click on 'show Passwords'

Please report back on whether you need to toggle that setting to false and whether password was saved after restarting.

Before seeing the latest post from Toad-Hall I had been continuing to enter the password for the tertiary email pop3 account and ticking the 'save password' button. After two or three repeats of this I found that it was not again requested. On checking the saved passwords I found that the pop3 and smtp passwords for all three accounts are shown as saved.

All now working.

To be complete I looked at the Toad-Hall request and after a little investigating I found the 'Config Editor' button in 'Tools' > 'Options' > 'Advanced' [not as in your post]. The value of "mail.password_protect_local_cache" is now false. Problem solved itself?