It works here in 78.4.3/W10 (see picture). Test for a broken layout by running in safe mode (hold Shift when launching TB). Does the problem remain?

Thanks sfhowes Yes lauching Thunderbird in safe mode (I didn't know I could do that with shift key) solves the problem. What should I do, to solve it in normal enviroment ?

Launch again in safe mode, check 'Reset toolbars & controls', 'Make changes & restart'. Does the Send button show in normal mode?

Thanks sfhowes I started again in safe mode, select reset Tool bar and controls, select make change and restart. It didn't change anything. Problem is still there.

sfhowes, While starting in safe mode, I noticed there was another option disable all add-ons I did it and restart. Problem isn't fix Any clue ???

As you can see from the safe mode article, safe mode also disables hardware acceleration, so if it is enabled in normal mode (Options/General/Indexing), disable it, restart TB, and see if it makes any difference. If that still doesn't work, I may suggest you create a new profile. That may seem unnecessary, but the benefits outweigh the short-term hassle.

I did test with the French language pack, but the Send button still appears, so it's probably not a localization issue.

I tried your last suggestion First I disabled Indexing Second I disabled Indexing and acceleration mode It doesn't make any difference. As I'm fully sure the problem appeared after Nov. 11th. I e-mailed a friend to check if he encountered the problem on Nov 12th

I do remember there were 3 updates on Nov 11th on my PC

• one on Thunderbird
• one on W10 KB4580980
• one on W10 KB4586786

The W10 updates were quite long. I took 2 hours to get the PC back. Any idea ? I'm not familiar with creating a new profile. What does it imply regarding local storage of e-mails i want to keep ? Thanks in advance

Create a new profile from Help/Troubleshooting, about:profiles, add an account, and see if the Send button works correctly. Copy abook.sqlite from the old profile to the new one, with TB closed, to transfer Personal Address Book. If the new profile works correctly, local mail, contacts etc. can be copied from the old profile to the new. The old profile is unaffected and can be launched from about:profiles.

Many Thanks. The new profile works just perfect. I did copy the Local Folders and Feed from old profile to the new one. Is there anything else I should have copied ?

When looking at the old profile I found there was an Imap.free.fr folder which accounts for 31 Gbytes. This is incredible as I installed TB on this machine only in July this year. Two files in this folder INBOX-1 and Sent items account respectively for 17 and 7 Gbytes !!! Considering the new profile is working fine, I'll continue with it and if nothing appens I will delete the old on in two weeks, if it's still ok. Regards

Many Thanks. The new profile works just perfect. I did copy the Local Folders and Feed from old profile to the new one. Is there anything else I should have copied ?

When looking at the old profile I found there was an Imap.free.fr folder which accounts for 31 Gbytes. This is incredible as I installed TB on this machine only in July this year. Two files in this folder INBOX-1 and Sent items account respectively for 17 and 7 Gbytes !!! Considering the new profile is working fine, I'll continue with it and if nothing appens I will delete the old on in two weeks, if it's still ok. Regards

When an account is removed from TB, there is the option to delete the mail folders (not the default). This often helps users who remove accounts but wish they'd first backed up the mail.

Local mail and contacts are the main items to copy, but the rest is explained in this semi-dated article:

http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Thunderbird

If you remove the old profile, use the option in about:profiles.

sfhowes, Thanks again, TB is working just fine as before. However as I wrote yesterday I found the old profile (default profile) takes an anormous disk space, approximately 31 gigabytes after 5 moths of use. In this profile there are two files :

• INBOX-1 ---> 17 Gbytes
• sent items ---> 7 Gbytes

Both are located within ImapMail\imapfree.fr -- note free.fr is my Internet provider That means 75% of profile space is just used by these two file.

If I look at today new profile used disk space is just 4 Gbytes When looking at the detail used space sent items account for 2.6 Gbytes There is no trace of an INBOX file.

You told me I shouldn't disregard the default profile. I would appreciate to know if there is a way to understand what is stored under INBOX-1. If it is just all the mail I received I don't care. All important message are already stored in local folders. I do think I'll have to manage mail differently. Previously I did use WLM and mail filing was easily accessed, message by message under the specific folders. TB works differently and message can be accessed only thru TB. I have to take that into consideration and explolre the export facility and understand the stucture of the exportes folder.

Thanks again for your kind support

If you copy the INBOX-1 mbox file into Mail/Local Folders of the new profile, with TB closed, then restart TB, an INBOX-1 folder should appear under Local Folders in the Folder Pane. Same with the mbox file for the sent items. Mbox files are the large files with no extension, named after folders. They appear with a like-named index file with an .msf extension, but the msf file can be ignored when copying the mbox to Mail/Local Folders.