Can't send mail using Mail.app since update to Mavericks One morning Mail on my Mac was working perfectly. At noon, I upgraded to Mavericks, then I could not send mails anymore!

I could read my mails but not send them (though I changed nothing in the configuration). I get the message: "authentication failed"!

My SMTP servers (two of these university based) are ok… So either:


The new version of Mail is no longer pleased with the server credentials (though I checked these)
The new version of Mail sends wrong information (password), but since these are still here I am wondering if there is some encoding fancy in the protocol that is not working anymore (yes there are accented characters in these informations!)


What I can I do? Can I downgrade and load an earlier version of the Mail app?
I have had the same problem... Spent two days then found it so simple:


Open Mail.app and go to your SMTP account settings;
Click on the Advanced tab and change the authentication method to password;
Input your mail as username and the password;
Voilá! Outgoing mail traffic working!