(Hidden by Administrator)
Bug 538809 Comment 33 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
I can confirm that this bug still exists in Thunderbird 9.0.1. Exim is a popular SMTP server and its default configuration is to check for RFC compliance by connecting clients. bug 525643 suggests that Postfix (another popular server) is also quite picky.