My husband and I share an email account with both of our names as our default identity. I created two additional identities, each with just one of our names (so if, for instance, I want to send him a link to an interesting article, I'll put myname.sonic/net in the "From" field and hisname.sonic.net in the "To" field). This has worked fine in the past. Recently, we bought a new computer and at first I didn't create multiple identities, but just customized the default as needed. Eventually, though, I created the new identities and I also added all three identities to our address book. This is what happens: 1) If I fill in From myname and To hisname, the email in our inbox has myname for both From and Recipient (and vice versa) 2) Worse, if I fill in both From and To with "Hisname and Myname" (the default identity), the email in our inbox has Hisname as both the From and Recipient 3) Worst of all, whoever is the latest From , becomes the Recipient of all the emails in our inbox that have been received since adding the identities. Note: I just 1) deleted the address book listings and all the identities except for the default "Hisname and Myname" --> ""Hisname and Myname" as From and Recipient of ALL emails, not just the more recent one 2) then I tried adding Myname back to the address book and wrote an email with customized Hisname in the To field and Myname in the To field --> all emails now show Myname as both the From and Recipient. So, it appears that the name is being drawn from the address book rather than using the default identity.