Can message rules be automatically put in alphabetical order?

There's no built-in way to do that, and it wouldn't be a good idea for most people, since the filters run in the order they're listed, and if the order is changed they may not produce the desired results.

If you're handy with a text editor and careful, a plain-text filters rule files, "msgFilterRules.dat" can be found in your Profile, a separate one for each email account. This could be edited with a text editor and the blocks of rules could be moved around. This probably wouldn't be any faster than using the Thunderbird interface unless you used some fancy macros or scripting in the editor.

Thank you for responding to my question. Although I am sure there are reasons to have message rules in chronological running order, I have never used them in that way. I have had to create more than one rule for quite a few senders that have different "from" addresses for the same person and/or company depending on the subject matter of each message. I have only one folder for each person and/or company and I add the numbers 1,2,3 etc. after the same message rule name for multiple "from" addresses from the same person and/or company. ie If I receive messages from my friend 'Happy' and he uses 3 different sending addresses, I would have 3 message rules named Happy 1, Happy 2, and Happy 3 all directing each message to one folder named Happy. If the rules were not in alphabetical order, and I wanted to modify each rule for Happy, I would need to hunt through over a hundred rules 3 times to find each rule for Happy. With all the rules in alphabetical order, I would only need to alphabetically go to "H" to find Happy. In addition, each time I add a new message rule, I need to manually place it in the alphabetical list of rules. Having it automatically alphabetically placed in the list of rules would be a help.

I appreciate your suggestion concerning text editing but, I am not familiar with that at all.

Well, most people don't use Filters that way, which is probably why I've never seen the question come up before. But I can see how it would helpful for some users.

You can suggest new features here, and maybe the developers consider adding it in a future version:

https://connect.mozilla.org/t5/ideas/idb-p/ideas/label-name/thunderbird