The Write window 'contacts sidebar' usually does exactly as it says in the Address Book.

So if you wanted it sorted by Surname, first name with A's at the top.

open 'Address Book' 'View' > 'Show name as' > 'Last,First' 'view' > 'Sort by' > select 'Name' and 'Ascending'

The addresses are alphabetized in the address book. It is just on the contacts list side bar where they are not, but oddly enough they are in alphabetical order by how the email address is spelled out. Being in alphabetical order by email spelling isn't much help because email address don't necessarily correlate with peoples names so while the adress are in order, the peoples names are not.

I have Mail Merge addon, but do not have your issue. When you use File > Mail Merge, do you link to an address book or did you export the address book as a comma separated.csv file saved to a folder outside of thunderbird and then link Mail Merge to the .csv file ?

Previous comment was me just wondering if the method had effected the contacts Sidebar.

Try This: In a new Write message, please check this has been selected. In the Contacts Sidebar: You are seeing 'Email' as the column header. to the right of that is a drop down selector icon where you can select 'Name' or 'Email'. select 'Name'.

see image below did that work?

I've tried changing from just showing name only to showing both the names and the email. Taking off the email doesn't change how the names are displayed which is that they aren't in alphabetical order.

This problem wasn't present before installing the mail merge add.Maybe I failed somewhere by storing lists of addresses in a document folder as backups.

I have done a mail merge with the add-on and it worked very well. I may need to try un-installing the mail merge add-on and see what takes place but I'll likely wait awhile before try that.

You can just disable an addon rather than uninstall it. Tools > Addons Mail Merge click on disable You would need to do a restart. This would test to see if only Mail Merge was causing the issue.

This will perform a restart with ALL addons disabled - not uninstalled. Start Thunderbird in SAfe Mode. Help > Restart with addons disabled.

But I would like to know if the Mail Merge is linking to the address book or a .csv file ?

Actually the problem is now mostly solved thanks to your suggestion about just doing a disable of the add-ons. I did what you suggested and the contact side bar in "write" was back to normal! To answer your question about how the lists were being saves, they are saved as LDIF files. Since I don't use mail merge very often, is there a way I can disable just Mail Merge 4.1.0 alone?

Your guidance was very helpful in being able to nail down the root cause of my problem Thank you.

I found our how to disable just the Mail Merge 4.1.0. I also found that disabling any or all of the extension that I have in Thunderbird (Lightening, Mail Merge and Stationary) did not reset the contacts side bar into alphabetical order. The only way I was able to achieve alphabetical order in the contact side bar was when I was operating in Safe Mode.

So It must have something to do with a setting but I've run out of things to try there. What I'll try next is posting my experience on Mozilla support and see if anyone else might see this question and possibly have some insights.

Once again, you have been a great help...Thank You!

fave you tried clicking on Name in the heading?

Yes, that has been tried. The answer is likely to be somewhere in a setting because when all the add ons in Thunderbird are disabled, and the computer is running in safe mode, the names in the contacts sidebar list are alphabetized. Not in safe mode, only the email addresses are in alphabetical order.

This is Thunderbird safe mode your talking about I assume. That means that there is an add-on involved. When you start in safe mode make the changes permanent and then restart.

I appreciate your idea. I'm am looking to fix the problem at its' root cause.

I would appreciate hearing form anyone who has encountered the problem I've described. I'd even like to hear from you even if the problem wasn't resolved if all you had to say was "I never found an answer".