With all respect for – in my humble opinion – best OpenSource mail client available for Windows platform, Mozilla Thunderbird – there is one bug or feature (the name depends of the users point of view) which drives me crazy. I’m talking about ‘Domain Name Mismatch’ dialog that is shown when Thunderbird connects to mail server via SSL and this server has self-issued SSL certificate. This is common setup in some hosting companies – they have one common self-issued certificate for whole server (including vhosts).From encryption point of view – this setup is not secure, but at least the transmission is encrypted. Anyway – every email client on the market issues an warning about this. But… Microsoft Outlook allows user to allow to use that kind of certificate and remembers user’s choice for whole session. Thunderbird is asking about it every time it connects to the mail server. Now imagine when the automatic check for new messages is set for for example – 5 minutes. Every 5 minutes Thunderbird shows modal dialog with ‘Security Error: Domain Name Mismatch’ error and asks for user’s decision. Believe me – it is very annoying. If user accidentally miss this dialog – for example other application catch the focus – Thunderbird waits for decision endlessly. Of course during this break no other actions can be processed by Thunderbird even on the other accounts. I would like to have a possibility to remember my choice by Thunderbird in any logical way – by checkbox, entry in configuration, additional xml file – whatever, and not to press ‘OK’ every 10 minutes. Of course I can always drop SSL connection and use normal one – but for me personally it is far less secure than SSL with wrong certificate. Moreover, there are more users affected by this ‘feature’ than me – just check this lengthy discussion on Mozilla’s Bugzilla. What is funny – discussion about this feature has started on 2003-12-16. We have now 2006-01-10 and they still are discussing about this. With all respect for Thunderbird Developers – let’s take user opinions under the consideration and just implement an solution for that problem. Thanks in advance.