OK, en tout cas ce n’est pas le cas chez nous. J’avais justement fais exprès de configurer l’option smtp_address_preference = ipv4
pour que les emails passent chez Gandi ou Cloudflare (voir mon commentaire). Comme attendu on envoie quasiment plus qu’en IPv4 et pas de problème du côté de gmail :
$ grep 'to=<.*gmail\.com>' /var/log/mail.log | tail |sed 's/<.*@gmail\.com>/<*****@gmail.com>/'
Feb 27 16:44:49 club1 postfix/smtp[3551244]: 98B8F41C4A: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=1, delays=0.06/0.12/0.44/0.42, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048689 f8-20020a05600c154800b004129f121243si3853557wmg.37 - gsmtp)
Feb 27 16:44:49 club1 postfix/smtp[3551245]: 9F0F541D5E: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=1.1, delays=0.08/0.13/0.37/0.48, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048689 x9-20020adfdd89000000b0033db5b62871si3998902wrl.290 - gsmtp)
Feb 27 16:44:49 club1 postfix/smtp[3551211]: 45CE140408: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=1.5, delays=0.22/0.04/0.77/0.5, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048689 v18-20020a05600c471200b00412a283b2e0si3169961wmo.182 - gsmtp)
Feb 27 16:44:52 club1 postfix/smtp[3551248]: D9BF941C2F: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=0.76, delays=0.08/0/0.07/0.61, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048692 a16-20020a5d53d0000000b0033d26b733f0si3983793wrw.890 - gsmtp)
Feb 27 16:44:54 club1 postfix/smtp[3551211]: 637C1428D4: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=0.79, delays=0.07/0/0.11/0.61, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048694 b13-20020adff24d000000b0033b7878dcc5si3713039wrp.870 - gsmtp)
Feb 27 16:44:54 club1 postfix/smtp[3551249]: 7E212428E6: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=0.73, delays=0.05/0/0.11/0.58, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048694 w14-20020adfcd0e000000b0033d20bb7f1asi4046654wrm.144 - gsmtp)
Feb 27 16:44:54 club1 postfix/smtp[3551297]: A205942993: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=0.72, delays=0.15/0.08/0.08/0.42, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048694 w10-20020a5d4b4a000000b0033d1468bc2csi3937014wrs.662 - gsmtp)
Feb 27 16:44:54 club1 postfix/smtp[3551291]: 8939042988: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=0.86, delays=0.17/0.07/0.09/0.53, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048694 c6-20020a056000184600b0033df44e8cbbsi627588wri.248 - gsmtp)
Feb 27 16:44:54 club1 postfix/smtp[3551300]: A14074298B: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=0.94, delays=0.16/0.11/0.07/0.6, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048694 u4-20020adfeb44000000b0033d754773cdsi4001701wrn.52 - gsmtp)
Feb 27 16:44:54 club1 postfix/smtp[3551278]: ABAD342A30: to=<*****@gmail.com>, relay=gmail-smtp-in.l.google.com[66.102.1.26]:25, delay=1.2, delays=0.14/0.38/0.09/0.57, dsn=2.0.0, status=sent (250 2.0.0 OK 1709048694 a16-20020a5d5710000000b0033ce73a5a84si3872200wrv.448 - gsmtp)