Changed (@verizon.net) password to abcd. Thunderbird only takes "Abcd" to pull or push mail.

Very strange problem changing a Verizon password & using Thunderbird SMTP and POP servers and ports are correct, because Thunderbird PULLs & PUSHES the mail fine. - made my password abcd (for example). - I can Pull & send/push netmail.verizon.net mail all day long in browser. Now onto Thunderbird (latest 31.2 but this has happened earlier (months) since I changed my password) NOTE: Since I pop up the Thunderbird password dialog (for Verizon) EVERY TIME (no saved passwords), I manually type it EACH time into the dialog. So, in Thunderbird, I tried "abcd" (after @Verizon.net password change), and it DID NOT WORK... But, being that we have to sometimes have capitalize passwords, I thought, well, maybe I forgot and made it "Abcd" - (Capitalize leading "a") - duh, so I tried that - AND IT WORKED... What the heck? First letter had to be capitalized for Thunderbird - though it WASN'T THE CORRECT @VERIZON.NET PASSWORD.