User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36 Steps to reproduce: 1. Create a new profile from the command line "thunderbird.exe -profilemanager" 1. Add a POP3 mail account 2. Write and send a message 3. click OK in the 'Send Message Error' window 3. click the 'Confirm security exception' in the 'Add security exception' window 4. Send the message 3. Remove the account in 'Account Settings' 4. Don't close the 'Account Setting', and add the same POP3 mail account again by clicking the the 'Account Actions' button 5. Write and send a message Actual results: An alert shows "There is not enough disk space to download new messages. Try deleting old mail, emptying the Trash folder, and compacting your mail folders, and then try again". Sometimes, this alert will not show and everything is normal. Expected results: The message should be sent without any alert.

Sorry about the numbers in the steps, I should have correct them in the right order.

Why is there a sending error and a security exception needed in step 3? Is your SMTP server not setup correctly in TB? But that probably isn't related to the bug. When you recreate the account again, can you receive new messages?

(In reply to :aceman from comment #2) > Why is there a sending error and a security exception needed in step 3? Is > your SMTP server not setup correctly in TB? But that probably isn't related > to the bug. > > When you recreate the account again, can you receive new messages? The step 3 is not necessary I think. And the account can receive messages, just alerting not enough space. I have tested more times, and the direct way to reproduce the problem is to add a POP3 account, delete it in 'Account Settings' and add it in there again. Then try sending a mail and the bug shows. You can try it more times if it is not produced, but I am pretty sure the problem exists. If the alert shows, if the user still want to use the same POP3 account, it can be complicated for user to solve it. The only way to solve it is to close the software, go into Profile folder, delete panacea.dat (the folder cache) and restart the software again. I think this is a hidden but severe problem, and should be pay attention to solve it.

I've linked this to bug 454359. However, we have steps to reproduce here that should be tested. Rob, can you test the steps in a test profile?

Could not reproduce this (tried several times what was described in comment 3: https://bugzilla.mozilla.org/show_bug.cgi?id=1416662#c3 )

Thanks Rob. Kyle can you reproduce using version 60?

(other such bugs https://mzl.la/2OTgVmf )

Resolved per whiteboard