Please post complete SMTP settings and there may be some suggestions.

I give you the message and the setting of the SMTP.

The message indicates a relay error. This sometimes happens when an account is linked to the wrong SMTP server. I suggest inserting a unique description in Description field of SMTP server settings, such as the related email address, and then recheck the account setting pane that links to the SMTP server to verify that it is correct. A relay error indicates that the smtp server is identifying an email address that is different from the sending email address.

1srt thank you for your answer. 1rst server : The incoming server is with the adress club-internet like the out going (choose by default) and it's my adress used all times and from always. 2nd server : The incoming server is with un other adress ( @.sfr.fr) and the outgoing is the same than the first (lpma@club-internet.fr) with the settings. These settings are the same from always and it's only with the new version 115.8.1 that the problems appeared. I tried to change the second server adress with my second adres in @sfr.fr but the result was the same. Now I use the site of my provider SFR but I'd like to use again my Thunderbird adress.

The server error message disagrees with you. DId you follow my suggestion to change description field and then verify on account pane?

david, I don't kow wath I must change when you speak of the description field? You speak of the outgoing server and the server by default club-internet? Not of the 2nd server SMTP? I tried again and on message it's written for the delivery adress?

The error says you are sending from a yahoo address, but the SMTP server is for club-internet. See attached screenshot for description field. I suggest updating for both SMTP servers to have unique names so you can verify from account pane.

I asked you all these questions because I did it but it change nothing.

All the settings are the same for the to out going server. The only one diference is the name of the esrver one is in club-internet, the other in sfr.

Okay, please post screenshots of the account panes for each of the accounts, as that will show the link to SMTP server. Thank you.

I joint the 2 panels of the outgoing server. This morning there was a upgrading for Thunderbird but no change. This problem appear only with the new version 115.8.1 before nothing. Thank you for your help..

What I am requesting is screenshots of the account panes. To see one, highlight an account on main pane, rightclick and select 'settings' and click. The next pane will show the account name and at the bottom will be the link to the SMTP server. I had requested that you give each a unique name, yet it appears that you named both of them 'SFR / Neuf' - Give each a DIFFERENT name and then recheck the account panes to see if they are assigned to appropriate SMTP server.

David, I changed the description of the outgoing server in lpma like asked and I kept SFR / Neuf on the second. Now the descriptions are différent. It don't run. To see the 4 screenshots. I change the name of the outoing server of the SFR accout and I tried to send a message from this account with the former server and from the new server, in the 2 cases, it don't run?

Please pay attention to the details. Look at the email addresses on the SMTP servers. They are BOTH the same. You need to have the proper email address on each. How many accounts do you have? Your earlier post included a yahoo account. Is it still there? To repeat: the email address on each account must be the one that is also in the SMTP server setting. Putting unique names in description field does not do that, but it sensitizes whether you have them set up properly.

I change the adress of the outgoing server and I put the adress SFR on the server SFR, it don't run. I have only 2 adresses. I don't use the adress SFR, I use only the adress with club-internet. The adress in Yahoo wasn't mine, it was a test I did with the adress of my cousin. It was the message for an outgoing mail. For me, anythingis right. I asked SFR to see if it can't come from the box they say no. I looked on the french forum Gekozone and there is so the same problem. Thank you

Okay, I understand that the club-internet account is working, but the sfr.fr is not. What is the error message that you receive?

When I send a mail, I have this message for all mails outgoing. If I change the outgoing server port in 25, I can send mail only for SFR network (Club-internet, Neuf and so on). Now if I want to send a message I mus goon the site of SFR and use their site is the only one solution.

Why are you attempting to send a yahoo email when you stated previously that you do not have a yahoo account. You do not seem to understand that the SMTP server used MUST be the same email account as the email address in the email message. This is back to your first post and you still do not understand.

David, My problem is I can'y send mails. I don't try to send a mail Yahoo, I send a mail from my computer to a person who has an adress in Yahoo like gmail, wanadoo and so on. My problem is the outgoing server blocks all the outgoing mails. If I put a outgoing port 25, I can send mails to SFR networks only if not no possible to send mails with the upgrade 115.8.1. Before all was OK!

Okay, a final request: please post again a screenshot of the SFR account pane. Not the SMTP pane, but the account pane itself. Thank you.