I have more than one email account with different servers. I'm having trouble with replying to messages received from the gmail account. The 1º gmails are being forwarded to another 2º gmail email address and then delivered to T-Bird. In Account Settings> Outgoing Server, I have added the 1º gmail user name (email address) and gmail server (smtp.gmail.com) to the list and I have added the 2º gmail address to the list. Then in Account Settings>Manager Identities, I have added the gmail account I want to the list of identities. When I try to reply with the same Identity that originally received the email (1º), I'm asked to provide the password. However, when I enter the password associated with the 1º gmail account, get error "Login to server smtp.gmail.com failed" and the error "The message could not be sent using outgoing server (SMTP) smtp.gmail.com for an unknown reason. Please verify that your outgoing server (SMTP) settings are correct and try again." Shortly after I get an email message from Google, "Someone just used your password to try to sign in to your account from a non-Google app. Google blocked them, but ..." When I enter the password for the 2º gmail account, I get the same error messages. However, if I change the "from" to the email to which received the forwarded gmail, then the message is successfully sent. I want to reply with the Identity that initially received the email. How to do this? (BTW T-Bird was successfully letting me do this until a couple months ago and then after an update, it didn't work anymore) Thanks for help.