Fix a Thunderbird plugin

We have a Thunderbird plugin that has a few problems, and we need someone to fix those problems. The plugin is used for attaching a text message to some of the emails in an inbox. The attached message is stored on the mailserver (in a separate account), so that everyone connecting to the IMAP account to be able to see the attached text for all the emails and add/edit the attached messages. The plugin uses the email message ID and writes it together with the attached text in an email message in the "separate account". The problems are: - sometimes, an attached text appears to more messages, to which it doesn't belong to - when the plugin's connection to the mailserver is lost (even if it's for a second), the plugin disables the message sharing and we need to restart Thunderbird in order to use the message sharing again - in the options screen, the Server Name field is not saved from the first time you edit it. - it's possible for the plugin to have problems working with multiple email accounts, so that need to be investigated and fixed (it's related to the first problem above). Please bid only if you have some good Mozilla plugin language knowledge and you can help us with those issues. The plugin will be provided after you are assigned to the project.