Merci à vous !
voici d’autres infos qui pourraient (?) pt-être aider ?
cat /var/log/mail.info |grep 94E744E39
Aug 24 15:07:35 debian postfix/smtpd[19962]: 94E744E39: client=unknown[14.195.235.245]
Aug 24 15:07:35 debian postfix/cleanup[19968]: 94E744E39: message-id=D64DD4F3AE2A8E4A5658DF2B47E80425@mondomaine.tld
Aug 24 15:07:36 debian postfix/qmgr[22975]: 94E744E39: from=Melanie789@mondomaine.tld, size=8126, nrcpt=1 (queue active)
Aug 24 15:07:36 debian postfix/pipe[19970]: 94E744E39: to=moi@mondomaine.tld, relay=spamassassin, delay=0.68, delays=0.42/0.01/0/0.25, dsn=2.0.0, status=sent (delivered via spamassassin service)
Aug 24 15:07:36 debian postfix/qmgr[22975]: 94E744E39: removed
cat /var/log/mail.log |grep "14.195.235.245"
Aug 24 15:07:35 debian postfix/smtpd[19962]: warning: hostname static-245.235.195.14-tataidc.co.in does not resolve to address 14.195.235.245: Name or service not known
Aug 24 15:07:35 debian postfix/smtpd[19962]: connect from unknown[14.195.235.245]
Aug 24 15:07:35 debian postfix/smtpd[19962]: 94E744E39: client=unknown[14.195.235.245]
Aug 24 15:12:36 debian postfix/smtpd[19962]: timeout after END-OF-MESSAGE from unknown[14.195.235.245]
Aug 24 15:12:36 debian postfix/smtpd[19962]: disconnect from unknown[14.195.235.245]
Aug 24 15:16:30 debian postfix/anvil[19964]: statistics: max connection rate 1/60s for (smtp:14.195.235.245) at Aug 24 15:07:35
Aug 24 15:16:30 debian postfix/anvil[19964]: statistics: max connection count 1 for (smtp:14.195.235.245) at Aug 24 15:07:35
rien dans auth.log
un bout de mon main.cf :
smtpd_helo_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
reject_invalid_helo_hostname,
reject_non_fqdn_helo_hostname,
# reject_unknown_helo_hostname
smtpd_sender_restrictions =
reject_non_fqdn_sender,
reject_unknown_sender_domain,
reject_sender_login_mismatch
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf
smtpd_sender_login_maps = mysql:/etc/postfix/mysql-sender-login-maps.cf
myhostname = debian.mondomaine.tld
myorigin = debian.mondomaine.tld
mydestination = localhost localhost.$mydomain
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
relayhost =
J’ai fais un test pour voir si l’utilisateur indésirable était dans la base : non :
mysql> SELECT username FROM mailbox WHERE username='Melanie789' AND active = 1;
Empty set (0.00 sec)
SELECT username FROM mailbox WHERE username='Melanie789@mondomaine.tld' AND active = 1;
Empty set (0.00 sec)
sudo cat /var/log/dovecot.log |grep "Melanie789@mondomaine.tld"
sudo cat /var/log/dovecot.log |grep "14.195.235.245"
Rien 
Il me manque certains éléments que je ne comprend pas
merci à vous 
ps : je n’ai pas de DKIM… penses-tu que ça viendrait de là ? j’ai cru un moment… mais en lisant la definition d’un DKIM… je me suis dis que non
je vais tester ce que tu me dis
voici le résultat :
dmarc Record Missing --> oui je sais
dns SOA Refresh Value is outside of the recommended range
dns SOA Expire Value out of recommended range
Le reste est OK.
Merci
: