I have mailcow with postfix installed on hetzner cloud. I am not system administrator, just developer but I setuped somehow mail server and it seems working. Problem is ,that I dont understand, is that email is sending slow, about 10 seconds. For enduser this is bad experience so I am trying to resolve this. In logs I found this delay
postfix-mailcow_1 | Aug 21 10:21:03 mail postfix/smtps/smtpd[609]: warning: hostname mail......club does not resolve to address 2a01:...::1: Temporary failure in name resolution
postfix-mailcow_1 | Aug 21 10:21:03 mail postfix/smtps/smtpd[609]: connect from unknown[2a01:......:ae58::1]
postfix-mailcow_1 | Aug 21 10:21:03 mail postfix/smtps/smtpd[609]: TLS SNI mail......com from unknown[2a01:.....::1] not matched, using default chain
postfix-mailcow_1 | Aug 21 10:21:03 mail postfix/smtps/smtpd[609]: Anonymous TLS connection established from unknown[2a01:.....8::1]: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256
postfix-mailcow_1 | Aug 21 10:21:03 mail postfix/smtps/smtpd[609]: 5F7741C3E28: client=unknown[2a01:.....::1], sasl_method=LOGIN, sasl_username=support@.....com
postfix-mailcow_1 | Aug 21 10:21:03 mail postfix/cleanup[614]: 5F7741C3E28: message-id=<a5b86d0e4f82708f3e5b8bfa6c5e3d60@www.......com>
postfix-mailcow_1 | Aug 21 10:21:11 mail postfix/qmgr[342]: 5F7741C3E28: from=<support@......com>, size=7756, nrcpt=1 (queue active)
postfix-mailcow_1 | Aug 21 10:21:11 mail postfix/smtps/smtpd[609]: disconnect from unknown[2a01.....::1] ehlo=1 auth=1 mail=1 rcpt=1 data=1 quit=1 commands=6
postfix-mailcow_1 | Aug 21 10:21:11 mail postfix/smtp[615]: 5F7741C3E28: replace: header Received: from www........com (unknown [IPv6:.....:ae: Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 5F7741C3E28??for <etet@yopmail.com>; Fri, 21 Aug 2020 10:21:03 +0200 (CEST)
postfix-mailcow_1 | Aug 21 10:21:11 mail postfix/smtp[615]: 5F7741C3E28: to=<etet@yopmail.com>, relay=smtp.yopmail.com[87.....155]:25, delay=8.5, delays=8.2/0.04/0.16/0.09, dsn=2.0.0, status=sent (250 mail saved)
postfix-mailcow_1 | Aug 21 10:21:11 mail postfix/qmgr[342]: 5F7741C3E28: removed
so from 03 seconds to 11 seconds some waiting or I dont know what. Can someone please suggest what can I do?