With thanks, Patrick Palmer

I wish to access my emails through Thunderbird (in addition to Zimbra) . On a previous computer I had both providers working side by side without difficulty. However my attempted download of Thunderbird is thwarted by the message "you are about to override how Thunderbird identifies with this site. Legitimate banks, stores and other sites will not ask you to do this". My further investigations online suggest I should "check where my email is posted (My broadband connection is with Shell Energy) and if in the same domain as the mail server, create the security exception". I am not sufficiently computer literate to understand all this and Shell Energy say they cannot advise me. I do not wish to lose my existing email access via Zimbra and wish to continue using my email address. Would creating the security exception solve the problem and enable me to get both email services together? With thanks, Patrick Palmer