Use Bcc Instead

Z 5 z 5 gwězdkow pógódnośony

wót Flammabel dnja Sept. 8, 2011 · trajny wótkaz

This is one of the tools that are so useful and simple that you wonder why the feature is not included in the Thunderbild core itself. Sending out an email to loads of people with the recipients' addresses visible to everyone is not just very annoying, it can be a major breach of privacy protection. With this add-on installed, it just can't accidentally happen anymore.

The settings enable you to define your own level of restriction: You can set the maximum number of recipients in the "To" and "CC" fields that may pass without warning (10 by default), and you can choose wether you want to be just warned (default) or stopped when that limit is exceeded.

There's only one item left on my wishlist:
For some reason that is a mystery to me, Thunderbird still doesn't have a built-in mail redirect (= bounce) function, so an add-on, usually Mail Redirect, is required to fulfil this basic task. When one bounces mails using Mail Redirect, the Use Bcc Instead add-on doesn't work. I have no idea wether it would be complicated to make the two add-ons work together, but that would make it perfect.