Review for Standalone SeaMonkey Mail by wjcarpenter
Rated 5 out of 5 stars
For most things, you don't even have to think about it. The links just open up in your preferred browser. If something does open up in SeaMonkey browser, it's easy enough to get there.
One place it doesn't work is if you click on a link in an email header. (RSS feeds put the URL in a "Website" header. If it worked there, it would be even better.
To create your own collections, you must have a Mozilla Add-ons account.