Roundcube Smtp error 535


I can not send roundcube emails (install on my server)
I have the following message: “error smtp 535 authenticated failed”
I can see all the emails in the inbox.

I went to see the log (var / log / mail.log) and I get:

Feb 7 19:06:50 ns311907 postfix / smtpd [22901]: warning: SASL authentication failure: can not connect to saslauthd server: No such file or directory
Feb 7 19:06:50 ns311907 postfix / smtpd [22901]: warning: unknown []: LOGIN SASL authentication failed: generic failur

I do not know how to fix this problem, it’s been 3 days that I’m above …

Thank you in advance for your help.

Loaded: loaded (/etc/init.d/saslauthd)
For this command # systemctl status saslauthd i have :

Active: active (exited) since mar. 2018-02-06 22:29:57 CET; 21h ago

févr. 06 22:29:57 saslauthd[16241]: To enable sas…
févr. 06 22:29:57 systemd[1]: Started LSB: saslau…
févr. 06 22:31:38 systemd[1]: Started LSB: saslau…
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