Every now and then, after sending a message, I'll get a popup that tells me that Thunderbird is having problems saving the message to the "sent" folder. When this happens, it never does any good to re-try. I just have to hit "cancel" and know that that sent message won't be saved. This has gone on for years, but has been very infrequent. Today I caught one, and I noticed the host it was trying to use to save to the sent folder. The host was one I hadn't used for many years. I have had 2 host changes since that time. Realize that I have no trouble sending messages. MOST of the time, sent messages save correctly in all of my accounts (I have 8 of them). Because the issue of saving a sent message is so infrequent, I've never noticed if it happens on any one specific account or many of them. However, I've been through all of my outgoing servers and none of them is pointing to the old hosing account. I've had the same problem with draft messages occasionally too. Note, the hosting account that I saw it using was inmotionhosting.com. All of my outgoing server domains are for my domains. So, it looks like somehow Thunderbird is resolving my domain name to the hosting account. I don't know why it would do that. So, I went into the config editor in Advanced Settings and searched for "inmotionhosting.com". I found a bunch of entries of this type. All of them have a status of "user set", but I did not set them. mail.identity.id2.archive_folder "imap://my_user_name@[email protected]/Archives" There are 2 sets of Archives, Drafts and Sent, one for id2 and the other for id7. Of note, my domain in question here didn't even exist when I was with inmotionhosting. There is one more setting might be relevant: mail.server13.hostname "vps11395.inmotionhosting.com" It's the only entry that is the hostname only, and might have been used to construct the other strings. There are 5 entries for "server13" besides hostname. The others are directory, directory-rel, spamActionTargetAccount and spamActionTargetFolder. I notice these entries won't delete. What should I do to get rid of this erroneous server data?