Dear @aaPanel_Kern I have reset the mail password and tried to send it again but face the same issue My server allows me to send mail on another mail present on the same server, but don't send mail outside the server other mails. Kindly check the logs I have attached below and inform me. I shall be very thankful to you for your kindness.
Nov 26 08:45:53 webcarehouse postfix/cleanup[53293]: 4CC8A42190D: message-id=-------------@webcare.localdomain
Nov 26 08:45:53 webcarehouse postfix/qmgr[2317]: 4CC8A42190D: from=info@mail.com, size=765, nrcpt=1 (queue active)
Nov 26 08:45:56 webcarehouse postfix/bounce[53557]: warning: /etc/postfix/main.cf, line 68: overriding earlier entry: relayhost=
Nov 26 08:45:56 webcarehouse postfix/smtp[53169]: 4CC8A42190D: to=mail@gmail.com, relay=smtp.mailgun.org[34.150.216.144]:587, delay=3.3, delays=0.22/0/2.6/0.42, dsn=4.0.0, status=deferred (host smtp.mailgun.org[34.150.216.144] said: 421 Domain sandbox06091835221a4bdba1b37e3cad48d674.mailgun.org is not allowed to send: Sandbox subdomains are for test purposes only. Please add your own domain or add the address to authorized recipients in Account Settings. (in reply to DATA command))
Nov 26 08:45:58 webcarehouse postfix/smtpd[51426]: warning: unknown[87.246.7.78]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Nov 26 08:45:59 webcarehouse postfix/smtpd[51426]: disconnect from unknown[87.246.7.78] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:00 webcarehouse postfix/smtpd[50130]: warning: unknown[87.246.7.227]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Nov 26 08:46:01 webcarehouse postfix/smtpd[50130]: disconnect from unknown[87.246.7.227] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:02 webcarehouse postfix/smtpd[52998]: warning: hostname net6-ip78.linkbg.com does not resolve to address 87.246.7.78: Name or service not known
Nov 26 08:46:02 webcarehouse postfix/smtpd[52998]: connect from unknown[87.246.7.78]
Nov 26 08:46:05 webcarehouse postfix/smtpd[51426]: warning: hostname net6-ip227.linkbg.com does not resolve to address 87.246.7.227: Name or service not known
Nov 26 08:46:05 webcarehouse postfix/smtpd[51426]: connect from unknown[87.246.7.227]
Nov 26 08:46:12 webcarehouse postfix/smtpd[50743]: disconnect from localhost[127.0.0.1] ehlo=1 auth=1 mail=1 rcpt=1 data=1 commands=5
Nov 26 08:46:19 webcarehouse postfix/smtpd[51426]: warning: unknown[87.246.7.227]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Nov 26 08:46:20 webcarehouse postfix/smtpd[50130]: warning: hostname net6-ip227.linkbg.com does not resolve to address 87.246.7.227: Name or service not known
Nov 26 08:46:20 webcarehouse postfix/smtpd[50130]: connect from unknown[87.246.7.227]
Nov 26 08:46:20 webcarehouse postfix/smtpd[52998]: warning: unknown[87.246.7.78]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Nov 26 08:46:20 webcarehouse postfix/smtpd[51426]: disconnect from unknown[87.246.7.227] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:20 webcarehouse postfix/smtpd[52998]: disconnect from unknown[87.246.7.78] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:20 webcarehouse postfix/smtpd[50743]: warning: hostname net6-ip78.linkbg.com does not resolve to address 87.246.7.78: Name or service not known
Nov 26 08:46:20 webcarehouse postfix/smtpd[50743]: connect from unknown[87.246.7.78]
Nov 26 08:46:32 webcarehouse postfix/smtpd[50130]: warning: unknown[87.246.7.227]: SASL LOGIN authentication failed: Connection lost to authentication server
Nov 26 08:46:33 webcarehouse postfix/smtpd[50130]: disconnect from unknown[87.246.7.227] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:35 webcarehouse postfix/smtpd[51426]: warning: hostname net6-ip227.linkbg.com does not resolve to address 87.246.7.227: Name or service not known
Nov 26 08:46:35 webcarehouse postfix/smtpd[51426]: connect from unknown[87.246.7.227]
Nov 26 08:46:35 webcarehouse postfix/smtpd[50743]: warning: unknown[87.246.7.78]: SASL LOGIN authentication failed: Connection lost to authentication server
Nov 26 08:46:37 webcarehouse postfix/smtpd[50743]: disconnect from unknown[87.246.7.78] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:39 webcarehouse postfix/smtpd[52998]: warning: hostname net6-ip78.linkbg.com does not resolve to address 87.246.7.78: Name or service not known
Nov 26 08:46:39 webcarehouse postfix/smtpd[52998]: connect from unknown[87.246.7.78]
Nov 26 08:46:41 webcarehouse postfix/smtpd[51426]: warning: unknown[87.246.7.227]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Nov 26 08:46:42 webcarehouse postfix/smtpd[51426]: disconnect from unknown[87.246.7.227] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:50 webcarehouse postfix/smtpd[50130]: warning: hostname net6-ip227.linkbg.com does not resolve to address 87.246.7.227: Name or service not known
Nov 26 08:46:50 webcarehouse postfix/smtpd[50130]: connect from unknown[87.246.7.227]
Nov 26 08:46:50 webcarehouse postfix/smtpd[52998]: warning: unknown[87.246.7.78]: SASL LOGIN authentication failed: UGFzc3dvcmQ6
Nov 26 08:46:52 webcarehouse postfix/smtpd[52998]: disconnect from unknown[87.246.7.78] ehlo=1 auth=0/1 rset=1 quit=1 commands=3/4
Nov 26 08:46:52 webcarehouse dovecot: auth: Warning: auth client 0 disconnected with 1 pending requests: Connection reset by peer